December 22, 1925. Washington, D.C. "Dick Nash, Pony Ballet." (My first thought on seeing this: How did my vacation photos end up on the Internet?) 4x5 glass negative, National Photo Company Collection. View full size.

June 30, 1925. "Miss Dorothy Brautigam of the National American Ballet." National Photo Company Collection glass negative. View full size.

New York, 1917. "Washday on landship Recruit." Sailors doing their laundry on the Navy's pretend battleship moored at Union Square, used for recruiting during World War I. In back is the Automatic Vaudeville penny arcade, two of whose backers -- Marcus Loew and Adolph Zukor -- went on to found Metro-Goldwyn- Mayer and Paramount Pictures after a few years in the nickelodeon business. 5x7 glass negative, George Grantham Bain Collection. View full size.

Interior of the Holiday Shop record and camera store at the Roeland Park Shopping Center in Roeland Park, Kansas. View full size. [A fascinating member-submitted photo. Just the thing for a Saturday night. Like a number of the commenters below, I would place the date here around 1950-51. - Dave]

Houston, October 1913. Marion Davis, Messenger #21 for Bellevue Messenger Service. Fourteen years old. "Been messenger, off and on, for two years. Not supposed to go to the Reservation [Red Light] under sixteen years, but I do just the same. The boss don't care and the cops don't stop me." View full size. Photograph and caption by the indefatigable Lewis Wickes Hine.

August 18, 1924. Washington, D.C. "Miss Beatrice Beck, daughter of Solicitor General James M. Beck." View full size. National Photo Company Collection.

1862. The Peninsula, Virginia. "Lt. George A. Custer with dog." Photographs from the main Eastern theater of war, the Peninsular Campaign, May-August 1862. Wet plate glass negative, photographer unknown. View full size.

Washington, D.C., 1925. "Miss Mary B. Hoover." No further clues as to the significance of this person. [This just in: Miss Hoover is "an authority on the proper fitting of Children's shoes."] View full size. National Photo Company.