April 1941. "Chicago. Lunch wagon for Negroes." 35mm negative by Edwin Rosskam for the Resettlement Administration. View full size.

July 1938. "Ambridge, Pennsylvania. Scene in the alley on the east side of town." (A photographer? And the Internet? Please go away!) 35mm negative by Arthur Rothstein for the Resettlement Administration. View full size.

August 20, 1959. There was no Twitter in 1959, but you could carry a sign around. "Little Rock, Arkansas. Rally at State Capitol. Group protesting admission of the 'Little Rock Nine' to Central High School." Photo by John T. Bledsoe. U.S. News & World Report Photograph Collection, Library of Congress. View full size.

Little Rock, Arkansas, in 1958, in the midst of that city's school integration crisis. No caption or photographer credit, but the picture tells the story. View full size.

Spring 1948. Mooseheart, Illinois. "Children at Mooseheart, an orphanage run by the charitable organization Loyal Order of Moose." From a series of photos taken by Stanley Kubrick, the future film director, for "Mooseheart -- The Child City," an article in the June 8, 1948, issue of Look magazine. View full size.

Atlantic City circa 1907. "Seaside Hotel (Seaside House)." Note the fly netting on the horse. 8x10 inch glass negative, Detroit Publishing Co. View full size.

1924. "Washington baseball." The Nationals, a.k.a. the Senators, at Griffith Stadium. Harris & Ewing Collection glass negative. View full size.

October 1948. "Bathing suit models in swimming pool." Bikini much? Not atoll. Anyone seen my gingham handkerchief? Photo by Toni Frissell. View full size.

1952. Motorcade to nowhere: Democratic presidential candidate Adlai Stevenson in San Francisco. Photo by Bob Lerner for Look magazine. View full size.

Batman and Robin (Adam West and Burt Ward) on the "Batman" set in Los Angeles in 1966. Who can explain the significance of the "22"? From a series of photos taken by Richard Hewett for Look magazine. View full size.

Atlantic City circa 1913. "Chalfonte Hotel." Here we are back at the beach, but with nary a pig in sight. 8x10 glass negative, Detroit Publishing Co. View full size.

New York, 1909. "Greek Festival -- Gladys Mumford, Mary Meyers, Susan Dresser, Elise Holmes, Mary French, Alice Richard, Gladys Robbins." The theme here is classical antiquity, although Miss Holmes betrays a certain Cubist insouciance. 8x10 glass negative, Bain News Service. View full size.

Jan. 27, 1947. "Kartch's, Main Street, Paterson, New Jersey. Interior rear, horizontal detail." An elaborate display of clothes and accessories for the baby in your life. Large-format acetate negative by Gottscho-Schleisner. View full size.

An uncaptioned photo from a group of pictures taken by Edwin Rosskam in the Northeast in the late 1930s. Who can locate the intersection? View full size.

        UPDATE: This is perhaps the earliest known example of a pig photobomb. See the comments for details.

Circa 1904. "The beach at Seabreeze -- Daytona, Florida." Open-air showcase for the latest styles in bonnets, bathing-costumes, self-propelled runabouts and light rigs. 8x10 inch glass negative, Detroit Publishing Co. View full size.