Which US military force was all but annihilated during the battle of "Greasy Grass?"

The 7th Calvary was not "all but annihilated" . Over half of the 7th Cavalry survived. However, all those troopers with Colonel Custer were killed.

The 7th Calvary was not all but annihilated.

my brother was in the 101st Airborne during Vietnam

Native Americans do!

Player #272443, Vietnam was 1st Cavalry not 7th.

Does anyone know why it's called "greasy" grass? As a child, I saw this battlefield and only remember large expanses of normal looking field grass.