The map shows important points during the beginning of Confederate General John McCausland’s raid on Chambersburg, Pennsylvania, and the immediate period after.  McCausland was pursued by Union General William W. Averell.  These U.S. Civil War events took place during late July and early August 1864.
Sifton, Praed &amp; Company, Ltd. modified by TwoScarsUp
This is a portion of a 1912 map created by Sifton, Praed &amp; Co. that has been modified by TwoScarsUp in 2017.  The entire map can be found in the Library of Congress <a rel="nofollow" class="external text" href="https://www.loc.gov/item/99448878/">map</a>, and shows mostly Virginia and Maryland with small portions of Pennsylvania and West Virginia.