ap - arch

In this photo provided by the Library of Congress, Maj. Gen. Ambrose E. Burnside, officer of the Federal Army, shown sometime between 1860 and 1865, l...

In this photo provided by the Library of Congress, Maj. Gen. George G. Meade, officer of the Federal Army, sometime between 1860 and 1865, location un...

In this photo provided by the Library of Congress, Franz Sigel, officer of the Federal Army, shown sometime between 1860 and 1870, location unknown. (...

In this photo provided by the Library of Congress, Allan Pinkerton ("E. J. Allen") of the Secret Service on horseback during the Battle of Antietam in...

In this photo provided by the Library of Congress, Confederate fortifications with Federal soldiers in Manassas, Va., in March 1862. (AP Photo/Library...

In this photo provided by the Library of Congress, the Drum Corps of the 93rd New York Infantry in Bealeton, Va., in August 1863. (AP Photo/Library of...

In this photo provided by the Library of Congress, generals of the Army of the Potomac in Culpeper, Va., in September 1863. Left to right: Governeur K...

In this photo provided by the Library of Congress, the guard mount of 114th Pennsylvania Infantry (1st Division, 3rd Corps), in Brandy Station, Va., i...

In this photo provided by the Library of Congress, rear view of the camp of Captain John J. Hoff of the Union Army in Gettysburg, Pa., in July 1865. (...

In this photo provided by the Library of Congress, Gen. Leonidas Polk, an officer of the Confederate Army, shown sometime between 1860 and 1864. (AP P...

In this photo provided by the Library of Congress, Jubal A. Early, an officer of the Confederate Army, shown sometime between 1860 and 1870, location...

In this photo provided by the Library of Congress, John Wilkes Booth, holding a cane, shown sometime between 1860 and 1865, location unknown. Booth as...

In this photo provided by the Library of Congress, Braxton Bragg, an officer of the Confederate Army, shown sometime between 1860 and 1870, location u...

In this photo provided by the Library of Congress, Gen. Joseph E. Johnston, officer of the Confederate Army, shown sometime between 1860 and 1865, loc...

In this photo provided by the Library of Congress, Brig. Gen. John Pope, officer of the Federal Army, circa 1861, location unknown. He was appointed M...

In this photo provided by the Library of Congress, Maj. Gen. Henry W. Halleck, officer of the Federal Army, shown sometime between 1860 and 1865, loca...

In this photo provided by the Library of Congress, David E. Twiggs, an officer of the Confederate Army, shown sometime between 1860 and 1862, location...

In this photo provided by the Library of Congress, participants and crowd at the first inauguration of President Abraham Lincoln, at the U.S. Capitol...

In this photo provided by the Library of Congress, Maj. Gen. Ulysses S. Grant, officer of the Federal Army, shown sometime between 1860 and 1865, loca...

In this photo provided by the Library of Congress, Maj. Gen. Joseph Hooker, officer of the Federal Army, shown sometime between 1860 and 1865, locatio...

In this photo provided by the Library of Congress, Major General Joseph Hooker, seated on horse, wearing military uniform, two tents and large buildin...

In this photo provided by the Library of Congress, 110th Pennsylvania regiment at Falmouth, Va., April 24, 1863, nearly annihilated at Battle of Chanc...

In this photo provided by the Library of Congress, President Abraham Lincoln's Gettysburg Address, in Gettysburg, Pa., on Nov. 19, 1863. (AP Photo/Lib...

In this photo provided by the Library of Congress, Major General Philip Sheridan and his generals in front of Sheridan's tent in 1864, location unknow...

In this photo provided by the Library of Congress, wounded soldiers from the Battle in the "Wilderness" at Fredericksburg, Va., May 20, 1864. (AP Phot...

In this photo provided by the Library of Congress, Confederate prisoners captured at the Battle of Fisher's Hill, Va., in September 1864, sent to the...

In this photo provided by the Library of Congress, Ford's Theatre, scene of the assassination of President Abraham Lincoln, in Washington, D.C., in 18...

In this photo provided by the Library of Congress, President Abraham Lincoln, seated and holding his spectacles and a pencil on Feb. 5, 1865. (AP Phot...

In this photo provided by the Library of Congress, Frank M. Welch, African-American, Maj. Cmdg 5th Battalion, CNG, shown in Bridgeport, Ct., circa 188...

In this photo provided by the Library of Congress, Gen. Pierre G.T. Beauregard, an officer of the Confederate Army, shown sometime between 1860 and 18...

In this photo provided by the Library of Congress, Maj. Gen. George B. McClellan, officer of the Federal Army, and his wife, Ellen Mary Marcy, shown s...

In this photo provided by the Library of Congress, Brig. Gen. William W. Averell, officer of the Federal Army, shown sometime between 1860 and 1870, l...

In this photo provided by the Library of Congress, Maj. Gen. William S. Rosecrans, officer of the Federal Army, shown sometime between 1860 and 1865,...

In this photo provided by the Library of Congress, Gen. Robert E. Lee, commander of the Confederate Army during the Civil War, shown between 1860 and...

In this photo provided by the Library of Congress, Gen. James Longstreet, an officer of the Confederate Army, shown sometime between 1860 and 1870, lo...

In this photo provided by the Library of Congress, Maj. Gen. John M. Schofield, officer of the Federal Army, shown sometime between 1860 and 1865, loc...

In this photo provided by the Library of Congress, Admiral David Glasgow Farragut, officer of the Federal Army circa 1862. (AP Photo/Library of Congre...

In this photo provided by the Library of Congress, General Sherman's troops are shown removing ammunition from Fort McAllister, near Savannah, Ga., in...

In this photo provided by the Library of Congress, view of the town and railroad bridge in Harper's Ferry, West Virginia between September 17 and Octo...

In this photo provided by the Library of Congress, a dead Confederate sharpshooter in "the devil's den," Gettysburg, Pa., in July 1863. (AP Photo/Libr...

In this photo provided by the Library of Congress, winter quarters at Brandy Station, Va., in December 1863. Left to right: Capt. Samuel A. McClellan,...

In this photo provided by the Library of Congress, a view of a store front with a sign reading "Auction & Negro Sales," on Whitehall Street in Atlanta...

In this photo provided by the Library of Congress, Federal troops are shown in a Confederate fort in Atlanta, Ga., in 1864. (AP Photo/Library of Congr...

In this photo provided by the Library of Congress, Gen. William T. Sherman, leaning on breach of gun, and staff at Federal Fort No. 7 in Atlanta, Ga.,...

In this photo provided by the Library of Congress, Gen. William T. Sherman shown on horseback at Federal Fort No. 7 in Atlanta, Ga., in 1864. (AP Phot...

In this photo provided by the Library of Congress, general view of the burned district in Richmond, Va., in April 1865. (AP Photo/Library of Congress/...

In this photo provided by the Library of Congress, President Abraham Lincoln's funeral on Pennsylvania Avenue in Washington, D.C., on April 19, 1865....

In this photo provided by the Library of Congress, General George Crook, officer of the Federal Army, shown between 1870 and 1880. (AP Photo/Library o...

In this photo provided by the Library of Congress, the everyday routine of camp life of the 31st Penn. Inf. (later, 82d Penn. Inf.) at Queen's farm, v...

In this photo provided by the Library of Congress, an artillery unit rides down Pennsylvania Avenue near the Treasury in Washington, D.C., during the...