|Illustration 1. The George Poffenberger farmstead, ca. 1896. The |
Hagerstown Pike is on the right.
There are numerous important resources available to the Antietam student--diaries, correspondence, ORs (well, mostly). Two resources that are key are the papers of Ezra Carman and the series of maps produced in 1904 and 1908  that depict movements throughout the day--some in 30 minute segments.
Recently, ANB Ranger Keith Snyder forwarded to me a photo of the West Woods taken from the Dunkard Church looking north up the Hagerstown Pike.
The photo is interesting in and of itself as it helps us understand the various changes this historic property has gone through over the past 149 years.
It also gives us some additional information on the value of the Cope-Carman maps. Note the detail on the extreme left of the image (illustration 2)--the fence line on the east side of the Hagerstown Pike. As you view the image, notice that the fence in the foreground is what is termed variably as a Virginia worm fence, zigzag rail fence, or snake fence. Further up the Pike, you'll notice that the fence changes to a pole fence (or post and rail fence) with the familiar horizontal rails. Now compare this fence sequence with the Cope-Carman map of 1908 (illustration 3)--it is the same sequence.
Detail from the Cope-Carman
Map, 8:00 series, 1908
edition, Library of Congress.
The zig zag lines on east
side of the Pike represent
the Virginia worm fence
while the dot-dash lines
represent the post hole
fence further north.
While I suppose I should not be surprised that the mapmakers got things right, the photographic evidence that they did so makes these maps all that more trustworthy and therefore valuable to historians, visitors, and trampers.
 The Maryland Campaign of September 1862: Ezra A. Carman's Definitive Study of the Union and Confederate Armies at Antietam, edited by Joseph Pierro (New York: Routledge, 2008). Historian Thomas Clemens is also producing a two volume edition of the Carman papers. The first volume, now published, is devoted to the South Mountain battles and contains many annotations and an excellent map series. Volume 2, on Antietam, will be going to press shortly. The Maryland Campaign of 1862. Volume 1, South Mountain, edited by Thomas Clemens (New York: Savas Beatie, 2010).
 The full citation of the Cope-Carman maps is: Atlas of the battlefield of Antietam, prepared under the direction of the Antietam Battlefield Board, lieut. col. Geo. W. Davis, U.S.A., president, gen. E.A. Carman, U.S.V., gen. H Heth, C.S.A. Surveyed by lieut. col. E.B. Cope, engineer, H.W. Mattern, assistant engineer, of the Gettysburg National Park. Drawn by Charles H. Ourand, 1899. Position of troops by gen. E. A. Carman. Published by authority of the Secretary of War, under the direction of the Chief of Engineers, U.S. Army, 1908. You can retrieve the entire series at the Library of Congress' American Memory Project at http://memory.loc.gov/cgi-bin/query/D?gmd:65:./temp/~ammem_u20M::