Frequently Asked Questions

How much stuff do you have, anyway?

To be blunt, we're not sure. We have acquired the records of other firms and absorbed them into our retrieval system, and we've been scanning right along, so the entire paper collection has never been in one building at the same time. (Once they are scanned, originals are transferred to the Maryland State Archives.) However, we can give some hints at the enormity of the pile: There are 230,843 directories (as of January 2021) comprising the digital collection. For a couple of reasons, it is not easy to get a precise count of the number of images, but there are well over 2.8 million, and the whole archive tree (comprised mostly of 50% jpeg images--which are small files) now comprises over 2.2 terabytes of data. An average of 50 megabytes of images are added each day. And we estimate that around ninety-five percent of what we control is now online.

What are the system requirements for this site?

Although we have tried to make our site usable on all systems, some of the functionality on the site assumes some things about your machine. First, we use javascript extensively, both for basic functionality (like The New Martenet Atlas) and for other enhancements meant to add polish to the site. If you have javascript turned off in your browser, a good percentage of what we have built will not work--if you can log on at all. Historically, some folks turned off javascript as a security precaution, but to a large extent any modern browser's javascript engine is pretty secure. We advise turning it on.

What are all these "Series?"

Because we had so much material to organize, it made sense to subdivide it into logical groups. (This is standard archival procedure.) If we had to do it all over again today, we likely would re-arrange some of the series designations, and fold some series into others, but, what's done is done.

Here is what is now in each series:
This series actually does not contain any records itself. It "points" to parts of records in other series. Here's why: some of our records contain pieces of information widely disbursed from one another geographically. Estate files (series 7) are a good example. Each "record" consists of one estate, but that estate may contain properties all over the region. Geographically indexing the entire estate would result in widely dispersed results, many of which being of no use to the researcher. To determine which images are relevant, the researcher would have to examine the entire estate. We chose instead to create this series which "groups" selected images and geographically indexes that group. However, once we realized the utility of such a technique, many other parts of records (or pointers to specific pages in books) were aggregated into sub-elements. These "records" live in Series 0, and are arranged in no particular order.
Records of City Property
For years the firm kept track of Mayor and City Council of Baltimore land transactions. In this series are ledger books describing each one. Also here are Water Department records concerning watershed land and the conduits from it.
Architectural Drawings
Recently we decided to organize architectural drawings of notable buildings, if the drawings came through our hands. This series is where they rest.
Martenet Wall Maps and Atlases
Here are the records for which the firm is famous among non-surveyors: the wall maps and atlases produced in the second half of the 19th century.
Martenet Packets
This is the big one. Here are all of the base survey files for the 56,000 or so surveys conducted by the firm over the years, and also the records returned to us from other surveyors who have used our data in their surveys.
Martenet Rolls
The oversized material that couldn't be folded up into a packet was rolled and stored here. (This amounts to a bit over 52,000 images segregated into 5,453 rolls.) Note that we lost all the extant rolls in the Great Baltimore Fire of February 7-8, 1904, so for the most part this material has been generated since then.
Martenet Fieldbooks
This series holds both the actual field notebooks carried on-site by the surveyors and the "Survey Record" books, maintained until about 1909, which document the final results of the surveys.
Estate Files
For a time, the firm was actively engaged in settling the estates of prominent Baltimoreans, such as John W. Garrett, William Wilkens and John S. Gittings. This series contains land title data, valuations, and sketches (or surveys) of all the real property in those estates.
Miscellaneous Records
This series is an eclectic collection of older data of interest to surveyors and historians, including the record books of 18th- and early 19th-century surveyors active in the area. Also here are the original Thomas Poppleton letters defending his approach to the 1822 survey of Baltimore. The early records of Baltimoretown and the Commissioners thereof are here. Finally, Charles Pielert's massive "Public Corporations of Baltimore City," containing charters, acquisitions (with deed references) and other material concerning many public service corporations is here. Most of these records and those of series 12 below are better organized and presented through our Contextual Resources portal, which is organized by county, and then topic.
Sutton, Britcher and Assocs. Files
The records of Howard C. Sutton, and of Sutton, Britcher and Associates, covering the period of 1922 through 1944.
E.V. Coonan & Co. Files
Edward V. Coonan (pronounced coo-NAN) worked here from 1894 to 1898, associated himself with the Bouldins for a time, and then launched his own firm. Operated until the 1960's, the firm's records thereafter remained in the possession of Russell Herbert, and later his son Ron. In 1995 the oversized plats (rolls) of the firm were given to us. We broke the 1,200 or so rolls down into 2,082 rolls, organized by location. Since Coonan had acquired the records of Thomas Disney, Disney's oversized plats are also in this series, as well as those of William Shipley, whose records Disney had obtained prior to his death. Shipley, in turn, had at least some of Richard W. Templeman's files, which are also here.
Purdum & Jeschke Files
Purdum and Jeschke was an engineering and surveying firm started in 1950 by William D. Purdum, that continued in operation until about 2001. In 2005, SJM purchased the surveying records. The engineering records remain in the custody of EBL Engineers.
Reference Materials
This is now a giant series which contains hundreds of published books of local laws, zoning and subdivision codes, local resident directories, histories, treatises, compilations, etc., all having full text search capability. It is most conveniently accessed through our Contextual Resources portal, which organizes the material geographically and then by topic.
Miscellaneous Maps and Plats
Here are the Railroad Valuation Maps for the region produced by most railroads beginning in 1919. We do not have a complete set, but we likely have more in one place than anyone else in Maryland save the National Archives in Silver Spring (which has them all!). Also here are Port Wardens' Line plats, Pierhead and Bulkhead Plats for the Baltimore Harbor, etc.
Baltimore City Ordinances
Baltimore City has published its ordinances and resolutions since 1797. Additionally, many of the volumes contain reports of various city agencies and commissions providing an in-depth understanding of the activites and issues confronting them. Here are scans of all of the volumes in the collection, dating from 1797 through 2008 and comprising over 100,000 images.
Records from Md State Archives
Occasionally we require information from the Maryland State Archives. This is where that data is stored.
Records from Baltimore City Archives
The City Archives has care of thousands of maps, plats and other records of proceedings concerning street openings, closings, miscellaneous surveys, etc. Some of the material had been microfilmed in the '60s and the originals destroyed. We have taken as many of those plats as have been digitized (over 6,000) and incorporated them into our system, with geographic indexing, etc. In most cases, it is easier to find a relevant plat on our system than at the Archives. We now have an ongoing project to scan and index the records of the actual opening and closing proceedings by the Commissioners for Opening Streets and their successors. These records are essential for determining the ownership and current status of streetbeds in Baltimore City. This is where that data is stored.
Bouldin Records
The Bouldins were the surveyors in the region from 1790 until Martenet showed up. Well, perhaps a bit longer than that! The firm finally ceased operations after the Great Baltimore Fire in 1904. The records were in the possession of the City until recently, when they were transferred to the Maryland State Archives. Later they came here for scanning and indexing. The scanning is complete (comprising 21,567 images), but the indexing has yet to begin.
Original City Plats
Here are the original subdivision plats covering the earliest developed areas of Baltimore City, most of which were prepared pursuant to Acts of the Maryland General Assembly.
Annex Plats
Baltimore City has expanded its limits a number of times, the last major one of which occurred in 1918. The subdivision plats lying within that part of Baltimore County transfered to the City were called "Annex Plats." Here they are, comprising 641 images in 7 plat books. Many of these particular sheets have been annotated with references to SJM files concerning the area or of marker placement.
Small Collections
Here we store smaller collections (under 500 files) of surveyors' records that we have acquired. Currently the records of George Chagetas are filed in this series.
Baltimore County Road Ledgers
Baltimore County maintained records of road openings and closings in a series of ledgers which we scanned and make available here. The material dates from 1829 through about 1916 and documents the origin, width, location and status of hundreds of roads within what is now Baltimore City, Baltimore County and Carroll County. This material has been geographically indexed and automatically appears in geographic search results.
Early Maryland Records
Here are the volumes of official records pertaining to the colonial Maryland government, and also the appellate court reporter volumes (e.g. Harris & Johnson, Gill, etc.) from 1658 through 1928. We found that obtaining copies of these records was a clunky, time-consuming exercise, and decided to incorporate them in toto into our archive, with full text search capability. Now getting copies is a snap!

You will notice that the Martenet-generated material is largely contained within Series 3 through Series 7.

What is in the subfolders, and why?

Modern survey file folders can get pretty large. Upon reflection, it occurred to us that the same sorts of material occur in most files, and, if grouped together, could make it easier for searchers to find what they seek. So we decided to subdivide some of our larger files into subsections (called subfolders). In general, here is what subfolders contain:

Computations concerning the survey.
Construction-support material, such as cut-sheets, etc.
Copies of earlier surveys and other data used in the survey.
Copies of recorded deeds used in the survey.
Copies of field notes or data collection print-outs.
Correspondence, legal descriptions written as a result of the survey, letters of transmittal, title commitments, etc.
In Estate file records, original descriptions of the lots to be distributed.
In Estate file records, original plats of the lots to be distributed.
In Estate file records, copies of the deeds comprising the estate of the deceased.

In the "root" of the record (i.e. not in the subfolders), will be the oversized material of the survey, drawings, etc. One note of caution: our sorting has not been perfect. Although we recommend starting your search using the descriptions above, do not assume that the record does not exist if not in the correct folder. Examine the other folders before abandoning the search.

I'm seeing "Sorry, your current access privileges do not extend to this record."

This message appears when the record you seek is not covered by the access privileges with which you accessed the site. There are a number of ways to access our site, some of which allow access to more data than others. The least restrictive access requires no login, but also displays very little data. Next in line is called an "Instance." An Instance is comprised of
  1. A certain user,
  2. A certain timeframe, and
  3. A certain geographic area.

Within those constraints, everything we have online is available to you. While in an active instance, unlimited geographic searches are allowed, but only records matching the geographic area of the Instance will be displayed. Alternatively, one can buy a "Subscription" for a period of not less than 3 months, which will allow unlimited geographic searches and also allow access to those parts of the site not focused on specific surveys (reference materials, generally). A Subscription will not allow display of most survey files; it is intended to be of use in determining whether we offer enough material in a particular area to warrant buying an Instance. One may buy any number of Instances while having an active Subscription, and we discount the price of those Instances. See details here.

There are no images in a record I want to see.

Converting our archive from paper records to digital records is a big job, and we've been working on various aspects of it since 1991. But it is not quite complete. See our upload status for details on what is online and what's not. We have some scanning ahead of us because of the sheer volume of material, coupled with our limited staff. If the record you seek is over 10 years old and essential to your current work, we will, for an additional fee, retrieve it and move it to the head of our queue. (We decline, for liability exposure reasons, to make files less than 10 years old available to others.) That will take at least a couple of business days or so (and sometimes longer, depending on our staffing abilities and on the nature of the record itself). Call our office for details. If your instance is scheduled to expire in the meantime, let us know, and we will extend the instance.

What's with all these letters and numbers like X1, B2 and K1W?

Those are the Martenet section numbers. Early in the life of the firm, Simon Martenet divided the metropolitan region into sections (like zip codes) for purposes of organizing the records. This served to speed subsequent archive searches. For reasons explained below, it is not necessary anymore to understand where the sections were, but for purposes of history, we'll explain it here anyway.

The Baltimore downtown area was designated K, and further subdivided into K1 and K2, Baltimore Street being the division line, and yet again K1E and K1W (east and west). South of the K's, I1 and I2 covered Locust Point and the land immediately to the west. Surrounding the K's and running counter-clockwise from the Fells Point area were A1, B1, C1, etc., to H1 in the southwest part of the inner city. These sections extended to the 1816 city limits (North Avenue, etc.). Extending those sections farther out to the 1888 city limits, radially, were A2, B2, C2, etc. Using major radial geographic features he subdivided the outer areas -- Harford Road is the division line between X1 (to the southeast) and X2 (to the northwest). X2 generally lies between Harford Road and the Jones Falls, etc. X3 is the northwest part of town, X4 the southwest. The X sections extend all the way out past the Beltway where they meet X5 which wraps completely around the others and covers the balance of Baltimore County. There are complicated division lines between X5 and the other X's. Other counties were all designated "MD." (Two other anomalies: First, we did so much work for the Canton Company, it got its own section, "CAN." You'll find no client entries in CAN packets for that reason. Second, out-of-state surveys and building interiors, etc., were grouped under the section MIS for miscellaneous.)

To search, one found the relevant section, then consulted index cards (one or more for each street in the section), such as at left. The entries on the card pointed to the packet, and the packet front page contained any additional references.

Both the physical packets and the oversized rolls were filed by section, and then chronologically in the case of the packets, and by roll number in the case of the rolls. All the packets and rolls have since been scanned and sent to the State Archives.

Our present geographic search capability largely obsoletes the Martenet-sections scheme of retrieval. It is no longer necessary to find which section contains the area of interest, because Map and Grid searches return all the records in that specific area. Moreover, as street names changed over the years, a more frequent occurance than might be imagined, the streets named on the index cards might not be the recognizable street name of today. We spent 14 years (and a pile of money!) re-indexing our archives using geo-coding, but we think the effort was worth it. The old system is now mostly a curiosity.

There is, however, one aspect of the section scheme that is still relevant: references to other papers in the files themselves will assume familiarity with the sections scheme. So, if in papers there is a reference to X2 10/24/1959, there is no way to retrieve that particular record except by entering that data on the "Martenet Records - Survey Records" page. Plat rolls are retrieved in a similar fashion on the same page.

Records of surveys conducted by the firm since 1988 use "SJM" as the section, and the project number as the "date."

How can I determine the correct Map and Grid?

The most sure way is to go to the New Martenet Atlas and find your location graphically. When you have found the area of interest, left click (once) and a pop-up will tell you the county, map and grid for the area (or block number in Baltimore City). Note that in some areas of the city our block numbers do not correspond to the city's block numbers. Where the city has single blocks covering a wide area, we have broken them down into smaller blocks, which makes for more precise record retrieval. In other areas the city has eliminated blocks now covered by Interstates or railroads, etc., but we have records pertaining to the underlying titles. We have resurrected the blocks in those areas to make those records accessible. Always check our Atlas when identifying which blocks will be pertinant to your search. Your browser must be set to allow pop-ups from And make sure you use the address instead of merely Omitting the leading "www" results in blank popup windows.

The county designations used are as follows:

Allegany: AL Anne Arundel: AA
Baltimore City: BC Baltimore County: BA
Carroll: CA Caroline: CR
Calvert: CV Cecil: CE
Charles: CH Dorchester: DO
Frederick: FR Harford: HA
Howard: HO Kent: KE
Montgomery: MO Prince George's: PG
Queen Anne's: QA St. Mary's: SM
Somerset: SO Talbot: TA
Washington: WA Wicomoco: WI
Worchester: WO Kent, Delaware: KT
New Castle, Delaware: NC Sussex, Delaware: SU
Washington, DC: DC Pennsylvania: PA
Virginia: VA

About those Keyword searches:

The keyword search box will return results on single or multiple word searches, separated by spaces. You may also refine the search results by adding a "-" prior to the search term. For instance, searching for titles "pratt washington -chapel" will return all results containing pratt and washington, except any that also contain the term "chapel." Search terms must be at least 4 characters long; shorter words are not indexed, and thus will return no results.

Our system also provides for "fuzzy" searches where the keyword does not have to have an exact match, only an approximate one. We use a method called metaphone, which indexes words by their pronunciation, for this functionality. It is not perfect, however, so you may need to try several spellings. Remembering that pronunciation is key, try entering in something that sounds like what you seek.

Searching for a particular client may be misleading. Often, but not always, our client was the attorney representing the landowner, not the landowner himself. The deed information within the record will reveal who the landowner was, but that information is not contained within the search fields. So a search for client "Martin Chuzzlewit" returning no results does not mean that we have no survey of his property. It just means that alternative search methods must be used to find it.

When I click on the "Generate pdf file" button nothing happens.

Our server has a number of security settings, one of which concerns the amount of memory any one "thread" can use. We have found that requesting pdfs of very large packets, or of large drawings, will exceed that memory limit. Once the threshold is reached, the operating system shuts the process down, and you get nothing. (We have increased the memory allocable to threads, but for some material that still isn't enough.) So, you'll have to generate pdfs of chunks of the file instead. In the box immediately to the left of the "generate pdf" button, enter the ranges of pages desired using dashes to describe the range limits and commas to separate the ranges. For instance, all of the following are valid entries:
1-4, 6-15, 34-36
The pdf will be generated in packet page order. In other words, in the third example above, the order of the pdf will be pages 2, 3, 4, 5, 6, 106, 107, 108 ... and so forth. Large packets can be printed in their entirety using this method, estimating between 50 and 60 pages per pdf. However, images with letters in their names, mostly oversized images with "os" in the name, will crash the partial-pdf generator. Print them out individually (for now).

When I click on a fieldbook and page reference nothing happens.

That link will open up a pop-up window with the image of the page. You must have javascript enabled in your browser and you must direct your browser to allow pop-ups from our site. Otherwise, it will not work.

What's with books 1 through 12? The pages seem to be from another book.

At some point in the distant past, books 1 through 12 were transcribed into 3 larger books labeled A, B and C. The pages in those later books listed the original book number on each page in Roman numerals, and the original page number in parenthesis. There is no correlation between the original page length and the transcribed page length, so the original page information might spill over onto one or more subsequent transcribed pages. The online retrieval system automatically accounts for the transcription, and will serve up the first page of the transcribed material.

These early books aren't really fieldbooks, are they?

No. They were actually "Survey Record" books wherein the final results of the survey were recorded. These books (numbered 1 through 26) were maintained up through about 1909. The packets in this era refer to the record books, not the actual field notebooks. The notebooks, which are also online, have very few references to them presently. One can find the actual field notes using the Field Book Cross Indices and some trial and error, but that is the only way to find particular notes. One day we'll go through the 300 or so fieldbooks of the period and link them to the packets pages.

I've seen "B.P." references in a fieldbook reference. What's that?

That's a "Back Page" reference. Basically, one starts at the back of the book and counts forward. Yeah, we don't know which dim bulb started that silliness, but there are a number of packets with those references. Most of these references now point to the correct page anyway. If you encounter any incorrect page hits, we'd appreciate a note indicating the correct page. We'll then update the link.

Some of the Series 5 rolls have geo references, but many do not. Why?

The paper system was set up such that the packets were indexed, and from them one found applicable rolls and fieldbooks. We patterned the digital system after that. There was no means, manually, to identify which packets referred to which rolls, except by looking at the packets themselves. So we never knew, for instance, whether 2 packets or 20 packets referenced a particular roll. In the database era, of course, searches like this are trivial. Imagine our surprise to learn that many rolls had no packets referring to them at all! This had the effect of dropping the rolls out of our geo-searches, because the packets were the primary search target. To rectify this situation, we have added geo references to those rolls having no packets referring to them. And only those rolls, at this time. The other rolls, presumably, can be found in a geo search through the packets.