Custer graduated from West Point in 1861, bottom of his class, but as the Civil War was just starting, trained officers were in immediate demand. He worked closely with General McClellan and the future General Pleasonton, who both recognised his qualities as a cavalry leader, and he was brevetted brigadier general of Volunteers at age 23. At Gettysburg, he commanded the Michigan Cavalry Brigade ("Wolverines"), and defeated Jeb Stuart’s assault on Cemetery Ridge, while greatly outnumbered. In 1864, Custer served in the Overland Campaign and in Sheridan’s army in the Shenandoah Valley, defeating Jubal Early at Cedar Creek. His division blocked Lee's final retreat and received the first flag of truce from the Confederates, Custer being present at Lee’s surrender to U.S. Grant at Appomattox.
After the war, Custer was appointed a lieutenant colonel in the Regular Army, and sent west to fight in the Indian Wars. On June 25, 1876, while leading the 7th Cavalry at the Battle of the Little Bighorn in Montana Territory against a coalition of Native American tribes, he was killed along with his entire detachment in an action known as "Custer's Last Stand".
His dramatic end was as controversial as the rest of his career, and his legacy remains deeply divided. His bold leadership in battle is unquestioned, but his legend was partly of his own fabrication, through his extensive journalism, and perhaps more through his wife’s energetic lobbying throughout her long widowhood.
Custer's paternal immigrant ancestors, Paulus and Gertrude Küster, emigrated to the North American English colonies around 1693 from the Rhineland in Germany, probably among thousands of Palatine refugees whose passage was arranged by the English government to gain settlers in New York and Pennsylvania.
According to family letters, Custer was named after George Armstrong, a minister, in his devout mother's hope that her son might join the clergy.