Source
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"Parade, Pennsylvania Avenue, Lincoln's Time.
Washington, DC, circa 1865., ca. 1910 - 1950 - NARA - 518225.tif."
http://en.wikipedia.org/wiki/File:Parade,_Pennsylvania_Avenue,_Lincoln's_Time._Washington,_DC,_circa_1865.,_ca._1910_-_1950_-_NARA_-_518225.tif
Wikipedia
Public domain.