Samuel Crawford was born in 1846 in Pennsylvania. He graduated from the University of Pennsylvania in 1850 and its medical school in 1851, joining the army as an assistant surgeon.

He was serving at Fort Sumter as the Civil War began, and commanded several guns during the bombardment in spite of being medical staff. Combat command apparently appealed to him, for shortly afterwards he accepted a commission as a Major in the Infantry. By 1862 he became a Brigadier General, leading an attack at Cedar Mountain that routed the Confederate Stonewall Brigade but cost Crawford 50% casualties.

Crawford was wounded at Antietam after briefly commanding his division. He didn't recover from the wound until May of 1863, when he was given command of the Pennsylvania Reserves, then recovering from hard campaigning by serving in the Washington defenses.

The Gettysburg crisis saw two brigades of the Reserves return to the Army of the Potomac. Crawford led them into the fighting around Little Round Top at the end of the day on July 2nd.

Crawford seizied the colors of the First Pennsylvania Reserves from a surprised Corporal Bertless Slot. After a brief struggle and with Corporal Slott running alongside his horse grasping his pant leg, Crawford led his division in a charge that cleared the Valley of Death and, in his estimation, saved Little Round Top.

Crawford remained in command of his division through the Overland campaign and the Siege of Petersburg and was again wounded at the Weldon Railroad. He was with the army at Appomattox, one of two men (the other General Truman Seymour) who could claim to be present at both the beginning of the war at Fort Sumter and its end at Appomattox.

After the war Crawford stayed on with the army until his retirement in 1873. He took a leading role in helping to develop Gettysburg as a memorial park. at one point purchasing land around Little Round Top to build a museum.

Crawford died in 1892 and is buried in Philadelphia.

Samuel Wylie Crawford