U.S. Army 1st Lt. Alonzo Cushing in his West Point graduation photograph dated 1861. Reuters

At his mother's behest, the headstone of U.S. Army 1st Lt. Alonzo Cushing in West Point Cemetery bears the inscription "Faithful Unto Death." Reuters

Margaret Zerwekh, 94, of Delafield, Wisconsin, listens as President Barack Obama awards the Medal of Honor posthumously to Army 1st Lt. Alonzo H. Cushing for conspicuous gallantry on Thursday. Obama acknowledged the work of Zerwekh, an amateur historian from Cushing's hometown, who painstakingly researched his story and lobbied Wisconsin's congressional delegation for decades. The Associated Press

President Barack Obama stands next to Helen Loring Ensign, of Palm Desert, California, a relative of 1st Lt. Alonzo H. Cushing, in the Roosevelt Room of the White House after presenting her with Cushing's posthumous Medal of Honor Thursday. Reuters

An Army officer holds the Medal of Honor before U.S. President Barack Obama presented it posthumously to U.S. Army 1st Lt. Alonzo H. Cushing for heroism during the Battle of Gettysburg. Reuters

An undated photo of 1st Lt. Alonzo H. Cushing, who died in July 1863 while standing his ground against Pickett's Charge in the Battle of Gettysburg.