Revised edition of the Loudoun County Section of this rare Civil War era survey of parts of Maryland and Virginia, conducted by the U.S. Topographical Engineers Office during the early stages of the American Civil War.
The map provides and exceptionally detailed treatment of Loudoun County and environs.
According to Rumsey, the map was issued in two editions in 1862, with a second and significantly revised edition appearing in August 1862. The first edition looks to be more of a proof state, with a different title and significantly less information than the later edition. There also appears to be an edition of this map which includes the following at the end of the title: "engraved on stone by J. Schedler", which is not present on the example of the map offered here, We note other areas where the map is not simply updated by is apparently revised.
Very accurate and dense map showing the country around and west of Washington, which was the first detailed map of Northern Virginia for use in the Civil War. The first edition appeared in January of 1862 (Stephenson 466) and extended further south to include Fredericksburg; this second edition extends south to Morrisburg. "Data Used in Compilation" appears in the upper left sheet and shows Surveys, Reconnaissances, Informations, Maps, Manuscripts, and Additions and Corrections. The first edition is plate 7:1, 8:1 in the "Atlas to Accompany..." Illustrated in Stephenson.
Link here to the Rumsey copy (4 sheets, state 2): http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~2250~160116:-Surveys-For-Military-Defences--Map
Link here to our example of the first state (2 sheets): https://www.raremaps.com/gallery/detail/34322
As noted by Rumsey, the map is exceptionally detailed and includes a table identifying the sources of information utilized for the map, providing a remarkable checklist of contemporary data for use by collectors in understanding the mapping and surveys being undertaken in the months and years immediately prior to the release of this map.
The later edition can be identified by quickly by the "Additions & Corrections" section at the bottom of the "Data Used in Compilation" section, which is not present in the earlier editions.