Preserving the Ephemeral at the GLO — Digitizing the John and Diana Cobb Map Collection

Texas General Land Office
Save Texas History
Published in
7 min readDec 19, 2022

As part of the General Land Office’s (GLO) mission to preserve Texas history for future generations and make accessible the historical documents that form the foundation of Texas’ public land system, the agency has spent over two decades digitizing its archival holdings and making them available online to the public. To supplement the collection, and to provide greater access to historic maps of Texas that are not in the physical holdings of the agency, the GLO has also entered into several partnerships with private collectors to digitize their collections. Since 2020, one such project has been the digitization of the John and Diana Cobb Map Collection.

John and Diana Cobb reached out to the GLO in 2019. They had become familiar with the agency’s mission through the Texas Map Society, and they recognized the opportunity to share their maps with a wider audience. The Houston couple, whose family roots include ranches in Wood, Taylor, Austin, and Wharton counties, have a long history of collecting things, from Gulf Coast seashells to antiques and Indigenous artifacts found on their homesteads. Their shared curiosity for family and Texas history pushed them to learn more about their land, and the couple developed an appreciation for early engravings about Texas, coastal surveys, and pocket maps. These interests coalesced to form the core of their collection: railroad and emigration maps.

John and Diana Cobb, owners of the Cobb Collection.

“The maps and pamphlets in the Cobb Collection provide an extensive view of railroads in Texas and the United States, a critical piece of the state’s nineteenth-century infrastructure and economic development. These maps are a perfect fit for the GLO’s existing collection because of the numerous tie-ins to the agency’s land-for-rail policies that helped to finance the earliest railroad construction in Texas,” said Mark Lambert, Deputy Director for the GLO Archives and Records. The railroad companies received large land grants, which incentivized them to also become enthusiastic spokesmen for Texas immigration, which they often advertised to the wider public, often through maps. Mark Lambert continued, “With the digital addition of the Cobb Collection to our website, alongside original maps at the GLO, researchers will have an unprecedented opportunity to learn about the cartographic history of railways in Texas like never before.”

John Cobb points to this as one of the elements that specifically drew him and Diana to railroad maps. Highlighting their ephemeral nature, he points out that “They were made to be used and then discarded. Many were made, but few have survived. They really have a personality designed to be a tool, and also to sell and market Texas and the land.” Diana Cobb continues, “I have enjoyed looking at the maps and brochures as we collected them. I particularly like the engravings for the glimpse into our past that they provide. It is rewarding having these maps and brochures scanned by the GLO so they can be shared with others.”

When asked if there were any maps of particular importance, significance, or interest, the Cobbs identified several that they found fascinating. These include an 1854 geological map showing the area from the Mississippi River to the Pacific Ocean and an 1877 map of the Missouri, Kansas & Texas Railway.

William P. Blake, Geological Map of the route explored by Lieut. A.W. Whipple, Corps of Topl. Engrs. near the Parallel of 35° North Latitude from the Mississippi River to the Pacific Ocean, Baltimore: A. Hoen & Co., 1854, Map #95750, Cobb Digital Map Collection, Archives and Records Program, Texas General Land Office, Austin, TX.

During the mid-nineteenth century, the U.S. government prioritized explorations for a railroad to reach the Pacific Ocean.[1] William P. Blake, the Pacific Railroad Exploring Expedition’s mineralogist and geologist, produced Geological Map of the route explored by Lieut. A.W. Whipple, Corps of Topl. Engrs. near the Parallel of 35° North Latitude from the Mississippi River to the Pacific Ocean (map #95750, 1854) for the U.S. Department of War.[2] The map details a narrow strip of land that A.W. Whipple’s expedition traversed, beginning in Napoleon, Arkansas, at the confluence of the Arkansas and Mississippi rivers, and ending in Los Angeles, California. At the bottom of the sheet, a color-coded key identifies the nine types of geological formations meticulously detailed on the map. As part of his work, Blake also researched the notes of Brevet Captain John Pope’s crossing of Texas from the Red River to the Rio Grande, which enhanced the available knowledge of the natural history of Texas and the American Southwest.[3]

[left] The map’s title block credits William P. Blake’s work on Lt. A.W. Whipple’s expedition from the Mississippi River to the Pacific Ocean. [right] Blake uses a color-coded scheme to detail geological features, including in this area around the Rio Grande.

“I particularly like the grading of geological formations as the railroad crosses the entirety of Texas. I have crossed the railroad from the Trans-Pecos through to Denison. It is my favorite railroad line and this survey of the natural history of Texas is very unique.” -John Cobb

Missouri, Kansas & Texas Ry. thro’ Denison and the beautiful Indian Territory, Chicago: Vandercook Co., 1877, Map #95805, Cobb Digital Map Collection, Archives and Records Program, Texas General Land Office, Austin, TX.

In the post-Reconstruction era, Texas’ railroad network grew extensively. Missouri, Kansas & Texas Ry. Thro’ Denison and the beautiful Indian Territory (map #95805, 1877) traces that railroad’s route and places it in context within the expanding rail networks of the Midwest and Great Plains. Beginning in Hannibal, Missouri, it passes through Indian Territory (present-day Oklahoma) and into Texas at Denison in Grayson County, then proceeds through the state’s center to Houston and Galveston. The map features numerous engravings by Paul Frenzeny and Jules Tavernier, artists in the employ of Harper’s Weekly who traveled to Texas via the MK&T.[4] The pair illustrate the beautiful natural landscapes railroad passengers could experience, as well as rail depots along the line and a view of a passenger coach accommodations. The map’s verso features additional advertisements, timetables, ticket prices, and other information.

[left] Among the map’s embellishments is this scene of the MK&T depot at Hannibal, Missouri. [right] The map includes a detailed timetable for an MK&T voyage from St. Louis, MO, to Galveston, TX.

“Once the railroad came into Texas, the engravings in the pictorials and books greatly improved in quality and accuracy. Two of my favorite artists, Frenzeny and Tavernier, came to Texas on the MKT. They published engravings of Texas and the West through to California. One of my favorite of their Texas engravings, A Deer Drive in the Texas “Cross-Timbers,” was published on February 28, 1874, in Harper’s Weekly, covering two whole pages.” -John Cobb

[upper left] Many pocket maps like this one suffer from separation at the folds after decades of use. They must be delicately unfolded for scanning. [upper right] The pocket map is unfolded and flattened using plexiglass panels. [lower left] Encased in its protective mylar sleeve, the scanning technician feeds the map through the large-format scanner. [lower right] Once the map is scanned, the process of digital image correction begins.

These two items are but a small portion of the Cobb Collection. As of the completion of the project, 206 PDFs were created, consisting of scans of 5,434 individual maps, books, pamphlets, documents, and pages. GLO Scan Lab technicians used multiple pieces of equipment that specialize in scanning large-format maps and books, taking great care to protect each item throughout the digitization process. After the scanning process was completed, staff performed quality control work including cropping, rotating, de-skewing, and color correcting before processing the images for online display. The Cobb Collection is available for viewing here.

“This has been a delightful experience learning about the GLO’s scanning process and the amount of work that goes into the project. We feel like our collection is really being used and appreciated.” -John and Diana Cobb

[left] The Cobb Collection features numerous booklets, some of which are featured here. [right] Scanning technicians use a special scanner to digitize books and other thicker media.

The General Land Office welcomes additional partnerships — if you would like to work with the GLO Archives to digitize your own map collection and preserve it online for future generations, please contact for a consultation.

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[1] The Transcontinental Railroad, History of Railroads and Maps, Library of Congress.

[2] Geographicus Rare Antique Maps, “Blake, William Phipps (June 1, 1826-May 22, 1910),”

[3] David B. Dill, “William Phipps Blake: Yankee Gentleman and Pioneer Geologist of the Far West,” The Journal of Arizona History 32, no. 4 (1991): 385–412.

[4] Robert Taft, “The Pictorial Record of the Old West: I. Frenzeny and Tavernier,” Kansas Historical Quarterly 14, no. 1 (February 1946): 1–35.



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