Major Dundee

In 1864, due to frequent Apache raids from Mexico into the U.S., a Union officer decides to illegally cross the border and destroy the Apache, using a mixed army of Union troops, Confederate POWs, civilian mercenaries, and scouts.
During the last winter of the Civil War, cavalry officer Amos Dundee leads a contentious troop of Army regulars, Confederate prisoners and scouts on an expedition into Mexico to destroy a band of Apaches who have been raiding U.S. bases in Texas.