Washington, D.C. "Alice Longworth & Paulina at circus. May 11, 1926." National Photo Company Collection glass negative, Library of Congress. View full size.

July 1936. "Drought refugees from Glendive, Montana, leaving for Washington state." View full size. Medium format nitrate negative by Arthur Rothstein.

August 1911. New Bedford, Massachusetts. "John Bachman, 22 Nelson Street, Ward 6. Works in drawing-in room at Acushnet Mill. 14 years old." Photograph by Lewis Wickes Hine. View full size.

East Guernewood, California, 1954. I'm 8 years old and hanging from the cherry tree in the front yard of our summer place at the Russian River. Looks like I've got a new pair of Keds or PF Flyers. 2-1/4 square Ektachrome transparency. View full size.

April 1865. Petersburg, Virginia. "Dead Confederate soldier outside the walls of Fort Mahone." Wet plate glass negative, left half of stereo pair, by Thomas C. Roche. Civil War glass negative collection, Library of Congress. View full size. There's a soundtrack and slide show for these photos here.

April 1865. Petersburg, Virginia. "Dead Federal soldier." Wet plate glass negative, right half of stereo pair, by Thomas Roche. Library of Congress. View full size.

April 3, 1865. Petersburg, Virginia. "Dead Confederate soldier in trenches of Fort Mahone." Wet plate glass negative, left half of stereo pair, by Thomas C. Roche. Civil War glass negative collection, Library of Congress. View full size.

April 1865. Petersburg, Virginia. "Dead Confederate soldier." Wet plate glass negative, right half of stereo pair, by Thomas C. Roche. View full size.

April 3, 1865. Petersburg, Virginia. "Dead Confederate soldier in trenches of Fort Mahone." Wet plate glass negative, right half of stereo pair, by Thomas C. Roche. Civil War glass negative collection, Library of Congress. View full size.

May 1912. Aragon Mills in Rock Hill, S.C. "Getting a last glimpse of out-doors before going to work at 1 o'clock." View full size. Photo by Lewis Wickes Hine.

May 1, 1923. Washington, D.C. "Children's Hospital Circus." View full size. National Photo Company Collection glass negative, Library of Congress.

February 1944. Pete Seeger singing at a Valentine's Day party to mark the opening of the United Federal Labor Canteen in Washington. View full size. Medium-format safety negative by Joseph Horne for the Office of War Information.

New York. March 21, 1913. Preparing for Circus Week at Madison Square Garden. 5x7 glass negative, George Grantham Bain Collection. View full size.

1925. "Condenser assembling department." Another view of workers putting radios together at the vast Atwater Kent factory in Philadelphia. View full size. National Photo Company Collection glass negative, Library of Congress.

Pittsburgh, August 1942. "The comforts of home looked pretty good to Navy Radioman John Marshall Evans and Sergeant French L. Vineyard, who spent Sunday with the family of their poster colleague George Woolslayer." Medium format negative negative by Alfred Palmer for the OWI. View full size.