Post Civil War, his Michigan Calvary was disbanded after a mutiny over Custer's' heavy handed disciplinary tactics which included using a whip on his men. In 1867 he was court martial ed, and found guilty of being absent from his men, and misusing some, to do an "unofficial escort", whereon in he abandoned some of his men, and caused their death. i.e. He was AWOL, and had abandoned his post to go and see his wife, taking soldiers for his own personal protection. Also in the proceedings, he was prosecuted for ordering a "shoot to kill" on his own men for desertion, and his unjustifiable cruelty to wounded soldiers.
He was given another command only because of his support from General Terry, and their short handedness, and was working in disgrace from his insults to President Grant, General William Sherman, and his division commander General Sheridan. This was due to his shady "trading post allocations".
His rise thru the ranks at such a pace was more due to the press pressure, loving his flamboyant dress, arrogance, and exaggerated battle stories to that press.
He was indeed regarded as a "Civil War Hero", but over time, his true character revealed him, as an arrogant glory hound, that had no respect for his men, or authority, and as this thread topic reveals, it eventually got him, and over 200 of his men killed.
As was Lincoln, Andrew Jackson, JFK and others. Custer has been maligned to be something, they and he, were not. Hollywood and the press, has played a major part in this distortion of "actual history".