"Post Office Department, Washington," circa 1908. The Old Post Office building seen from the corner of 11th Street and Pennsylvania Avenue N.W. on a rainy day. George Grantham Bain Collection glass negative. View full size.

"Union Square from a skyscraper." Winter in New York 100 years ago. A little moldy but full of interesting details like the "Automatic Vaudeville" penny arcade and Brill Bros. store. 5x7 glass negative, George Grantham Bain. View full size.

June 3, 1912. " Hampton Roads, Virginia. German squadron visit to U.S." Details of the port call here. Harris & Ewing Collection glass negative. View full size.

Washington, D.C., circa 1915. "P.K. Chaconas Co. Market." Pictured: Proprietor George Chaconas, whose grocery ("fancy fruits and vegetables") was at 924 Louisiana Avenue N.W. Harris & Ewing glass negative. View full size.

June 1942. Fort Knox, Kentucky. "The crew of an M-3 tank learns all the ways of causing trouble for the Axis with a 75mm gun, a 37mm gun and four machine guns." 4x5 Kodachrome transparency by Alfred Palmer, OWI. View full size.

"Loading bus, leaving Manzanar for relocation. Manzanar Relocation Center, California." Large format nitrate negative by Ansel Adams. View full size.

"Boy Scout training demonstration, 1912." The third photo so far in our series on Scout first aid. Harris & Ewing Collection glass negative. View full size.

Washington, D.C., in 1925. "Stoneleigh Court, L Street N.W." For some reason I feel like Jimmy Stewart here. National Photo glass negative. View full size.