[Ol'Grey Head]

Custer was the youngest man to be made a Brigadier General during the Civil War. How come he was a Lieutenant Colonel at the Little Big Horn?

[SAMWolf]

The wartime "brevet" ranks were "temporary" grades, and in the constriction of the military following the war, virtually all officers-like George Armstrong Custer, for example-reverted to lower, "permanent" ranks.