1864. Union Army soldier at Confederate fortifications outside of Atlanta. Wet collodion glass-plate negative by George N. Barnard. View full size.

January 1909. Two of the "helpers" in the Tifton Cotton Mill at Tifton, Georgia. They work regularly. View full size. Photo and caption by Lewis Wickes Hine.

June 1911. Ethel Shumate. Has been rolling cigarettes in Danville (Virginia) factory for six months. Lives at 614 Upper Street. Said she was 13 years old, but it is doubtful. View full size. Photograph and caption by Lewis Wickes Hine.

February 19, 1925. "M.S. Strock measuring radio lengths at the Bureau of Standards." View full size. 4x5 glass negative, National Photo Co. Collection.

May 1943. "Nearly exhausted sulfur vat from which railroad cars are loaded. Freeport Sulphur Company at Hoskins Mound, Texas." View full size. 4x5 Kodachrome transparency by John Vachon, Office of War Information.

May 1942. Another shot of Marines training with barrage balloons at Parris Island, S.C. View full size. 4x5 Kodachrome transparency by Alfred Palmer.

February 16, 1915. The boxer Leach Cross, "the fighting dentist," strikes a pose. View full size. 5x7 glass negative, George Grantham Bain Collection.

May 1942. Motor detachment at the New River, North Carolina, Marine base. View full size. 4x5 Kodachrome transparency by Alfred Palmer, O.W.I.

May 1942. Marine transport driver at New River, North Carolina. View full size. 4x5 Kodachrome transparency by Alfred Palmer, Office of War Information.

October 1942. B-25 bomber nose wheel and landing gear assembly at the North American Aviation plant in Inglewood, California. View full size. 4x5 Kodachrome transparency by Alfred Palmer for the Office of War Information.

June 1942. An M-4 tank at Fort Knox, Kentucky. View full size. 4x5 Kodachrome transparency by Alfred Palmer for the Office of War Information.

June 1942. An M-4 tank crew training at Fort Knox, Kentucky. View full size. 4x5 Kodachrome transparency by Alfred Palmer, Office of War Information.

Ed Smalle, "the singing comedian," at the keyboard circa 1922. View full size. 5x7 glass negative, George Grantham Bain Collection.

October 1908. South Bend, Indiana. "Going home to lunch! Two boys from Singer Manufacturing Company. Small boy is Charles Bailey, 316 Scholum Street. Is he 14 years old?" View full size. Photograph and caption by Lewis Wickes Hine.

August 14, 1924. President Calvin Coolidge and his radio-equipped Buick automobile in Washington. View full size. National Photo Company Collection.