President William McKinley's death mask

William McKinley (January 29, 1843 – September 14, 1901) was an American politician and lawyer who served as the 25th President of the United States from March 4, 1897, until his assassination in September 1901, six months into his second term. McKinley was the last president to have served in the American Civil War. He promoted the tariffs to protect manufacturers from foreign competition, and in 1900, he secured the passage of the Gold Standard Act. He led the nation in the Spanish–American War of 1898: the U.S. victory was quick and decisive. "The mission of the United States is one of benevolent assimilation."

In 1944 the D.C. Public Library purchased over 1800 lanternslides and glass plate negatives from E.B. Thompson for $1,000. Mr. Thompson was a photographer who in 1904 opened a store that sold “steropticon supplies, cameras, lantern slides,” and other photographic equipment at 1343 F St., NW. His camera shop moved numerous times in forty years, ending up finally at 1744 Columbia Road, N.W. In 1944, his business letterhead advertised his store as selling “Sound and Silent Motion Pictures and Slides”.He offered to sell his collection of images of Washington, DC to the DC Public Library as he prepared to retire from full time work after a long illness in 1944. Starting in 1946 the DC Public Library contracted with the Library of Congress to create 8x10 black and white prints on mounts from his collection of slides and negatives. The prints are now part of the Washington, DC Historical Image Collection in the Washingtoniana Division. The collection’s strengths are in its images of federal buildings, the Arlington National Cemetery, federal memorials, national parades, historic houses, and street scenes.