Anatomy Class circa 1905. Location unknown. View full size. George Grantham Bain Collection.

New York, December 1924. "Greenwich Village Follies Cooking Class." George Grantham Bain Collection. View full size.

Cooking Class for Men at the Pratt Institute with Miss Hanks and Miss Kierstead, circa 1917. View full size. George Grantham Bain Collection.

Electricity Class at St. George's Evening Trade School, New York, circa 1910. View full size. George Grantham Bain Collection.

P-51 Mustangs of the 332nd Fighter Group (Tuskegee Airmen). Ramitelli, Italy, March 1945. View full size. Photograph by Toni Frissell.

Old Ford's Theatre in Washington, D.C., where Abraham Lincoln was shot in 1865. View full size. Wet collodion glass plate. Photograph by Mathew Brady.

Federal soldiers killed July 1, 1863, near the McPherson woods. Gettysburg, Pennsylvania. View full size. Wet collodion glass plate, half of stereograph pair. Photograph by Timothy H. O'Sullivan.

View of ruined buildings through porch of the Circular Church at 150 Meeting Street, Charleston, South Carolina. April 1865. View full size. Wet collodion glass plate, half of stereograph pair. Photographer unknown. While much of the damage shown here is from shelling by the Federal Navy, the Circular Church itself was heavily damaged by fire in 1861. Alternate view.

Tuskegee airmen exiting the parachute room at Ramitelli, Italy. March 1945. From left: Richard S. "Rip" Harder, Brooklyn, Class 44-B; unidentified airman; Thurston L. Gaines Jr., Freeport, N.Y., Class 44-G; Newman C. Golden, Cincinnati, Class 44-G; Wendell M. Lucas, Fairmont Heights, Maryland, Class 44-E. View full size. Photograph by Toni Frissell.

The Park Row Building at 15 Park Row circa 1912. View full size. For nine years this 1899 tower, at 391 feet, was the tallest in New York. Read more here. Irving Underhill photo.

November 29, 1908. Boys working in the Eureka Cotton Mills at Chester, South Carolina. Rob Dover (tallest boy) has been in mill eight or nine years. Melvin Reilly (middle) in mill one year. Boyd McKowan is about 15 years old. Been in mill five years. Witness Sara R. Hine. View full size. Photo by Lewis Wickes Hine.

November 30, 1908. School in Lancaster, South Carolina, attended by children who work in the cotton mills. Enrollment 163. Attendance, usually about 100. These are all that attend out of the 1,000 employed at the mill. View full size. Photograph by Lewis Wickes Hine. View even larger.

Visitors at Marshall Hall, 1893. View full size. Photo by William Cruikshank. Marshall Hall, an estate and ferry stop across the Potomac from Mount Vernon, was a popular picnic and concert destination for day-trippers from Washington.

15-year-old sweeper in the spinning and spooling room of Berkshire Cotton Mills. Adams, Massachusetts. July 10, 1916. View full size. Photo by Lewis Hine.

Santa Fe freight about to leave for the West Coast from the Corwith Yard at Chicago. View full size. 4x5 Kodachrome transparency by Jack Delano. This is the freight Jack accompanied from Chicago to California in March 1943, taking many pictures along the way for the Office of War Information.