1864. "Federal cavalry guarding the Orange & Alexandria R.R. near Union Mills, Virginia." Wet plate glass negative by Mathew Brady -- National Archives. View full size.

May 24, 1865. "Washington, District of Columbia. The Grand Review of the Army. Units of XX Army Corps, Army of Georgia, passing on Pennsylvania Avenue near the Treasury." Wet plate negative by Mathew Brady. View full size.

July 1863. "Gettysburg, Pa. Three captured Confederate soldiers, likely from Louisiana, pose for Mathew Brady on Seminary Ridge following the Battle of Gettysburg." Wet plate glass negative, half of stereograph pair. View full size.

1863. "Hanover Junction, Pennsylvania. Passenger train at depot." From photographs of the main Eastern theater of war, Gettysburg, June-July 1863. Wet plate glass negative by Mathew Brady or his assistant. View full size.

May 1865. "Another artillery unit passing on Pennsylvania Avenue near the Treasury." Wet plate glass negative by Mathew Brady. View full size.

"Tom Thumb, full-length portrait, facing front, standing on table." Half-plate daguerreotype c. 1850-55 from the studio of Mathew Brady. View full size.

"Major General George Armstrong Custer, officer of the Federal Army" circa 1865. Wet plate glass negative, studio of Mathew Brady. View full size.

New York or Washington circa 1844-1851. "General Hugh Brady, head-and-shoulders portrait, facing three-quarters left, in military uniform." Half-plate daguerreotype from the studio of Mathew Brady. View full size.

Circa 1844-1860, another portrait sitter from the studio of Mathew Brady, this one with a striking amoeba-shaped chapeau. "Unidentified woman, head and shoulders portrait, facing front. Sixth-plate daguerreotype. Hallmark: Rinhart 31. Scratched on back of plate: 304. Same sitter as in Dag No. 116." View full size.

Circa 1844-1860 daguerreotype from the studio of Mathew Brady. "Unidentified man, head-and-shoulders portrait, facing slightly right." View full size.

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.

"Washington Monument as it stood for 25 years," 1860. Glass-plate (wet collodion) photograph by Mathew Brady. View full size.