This is a United States War Department map of the Droop Mountain battlefield, including positions of the Union and Confederate armies. The Battle occurred on November 6, 1863, with the Union force led by William W. Averell defeating a Confederate Force led by John Echols. The map's orientation is somewhat "upside down", as Hillsborough is actually northeast of Droop Mountain.
United States War Department (much of the work was done by Robert N. Scott, Joseph W. Kirkley, and Fred C. Ainsworth.
This is a page from the atlas portion of The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies. The entire atlas can be found in the Library of Congress <a rel="nofollow" class="external text" href="https://www.loc.gov/resource/g3701sm.gcw0099000/?sp=162">map</a>, and shows maps for several battles on image 162.  The LCCN Permalink is <a rel="nofollow" class="external text" href="https://catalog.loc.gov/vwebv/search?searchCode=LCCN&amp;searchArg=03003452&amp;searchType=1&amp;permalink=y">here</a>. Created from 1880 through 1901.