The maps McElfresh Map Company prepares and publishes are in the rather arcane genre known as “historical base maps” or in England as “reconstruction maps.” Our maps are primarily of Civil War and other battlefields but the data on the map relates 99% to the cultural and physical aspects of the field (the lay of the land in other words) with perhaps a brief reference to some military aspect of the field. For example, on an endpaper map we prepared for volume 1 of Library of America’s The Civil War: As Told By Those Who Lived It, the Bull Run map specifically labels the roundabout route the Union flank march followed to Sudley Ford. Otherwise the massive details presented on the map are interesting but insufficient to provide an understanding of the development and progress of the battle.

Questions are often raised about the process, in the 21^st Century, of determining the direction of some long vanished lane or the type of fence surrounding a field or the crop growing in it at Gettysburg in July 1863. Or Antietam in 1862. Or the wartime route of Stonewall Jackson enroute to Cedar Mountain. The question is, are these features accurate or speculative or just made up?

As I researched,I found some surprising resources available to accurately map a Civil War battle in amazing detail.

First: the photographs. William A. Frassanito in his extraordinary books on Gettysburg, Antietam, and the Overland Campaign, collected an enormous number contemporaneous photos and then performed the nearly impossible task of properly locating the vantage point of the photographer and identifying their actual location on the battlefield.

It was then possible for me to identify the types of fences: the post and rail fences were nearly impossible to pull down, so that was easy. Ditto for the board fences. Rock walls stayed put and the detritus along other fields would evidence worm/rail/Virginia type fences.

Further, in these vivid photos, crops in the field could be identified. Dale Dewing, a Cornell agronomist, studied the photos and, knowing the early July time frame, was able to distinguish among wheat, rye and oat fields. Scratchy corn fields were obvious. Orchards were orderly sets of trees.

Also clearly evident were barns, sheds, houses, toll houses, small wooden bridges over culverts…these photos, accurately located, were de facto indexes of the cultural and physical details of the featured battlefields. At Gettysburg, an additional invaluable resource was the isometric (or balloon view) map of the field prepared by John Bachelder in 1863. Bachelder arrived on the field shortly after the battle, interviewing the captive (literally) audience of wounded Confederates, the Union wounded, civilians and anyone with knowledge of the battle and the field.  Bachelder then established north/south columns and marched up and down them with a scroll of mapping paper, examining and recording the topographical features of the field as carefully as he did the comments of survivors and witness to the battle. He carefully depicted stone bridges, covered bridges and other encompassing details that no known photographs supplied.

Prior to the McElfresh map of Antietam battlefield, the “definitive” map since the 1880’s had been the Carmen/Cope map. A quick initial glance at this map in comparison with post battle photographs revealed numerous missing details…and that was just in the immediate vicinity of the Middle Bridge.  Missing on the earlier “definitive” map, just in this one tiny section of the field, were two substantial farmhouses, their outbuildings, a fenced in cornfield and a toll booth on the Boonsboro pike.  Again, the Frassanito Antietam study provided invaluable guidance.

The next mapping blogs will provide further incontrovertible resources to inform a 21^st Century mapmaker of the lay of the Civil War’s land, including such arcane and/or obvious resources as 20^th Century aerial photography, memoirs, burial maps, contemporaneous military maps, outdated USGS maps, regimental histories, bird droppings, orderly rocks and other peculiar but reliable resources.