Simplify the following text for a Grade 8 native English-speaking person.
Original: Union and Confederate units fought a battle at Columbus , Georgia before the April 16 , 1865 surrender and a small final battle at Palmito Ranch , Texas on May 12 , 1865 . In areas more distant from the main theaters of operations , Confederate forces in Alabama and Mississippi under Lieutenant General Richard Taylor , in Arkansas under Brigadier General M. Jeff Thompson , in Louisiana and Texas under General E. Kirby Smith and in Indian Territory under Brigadier General Stand Watie surrendered on May 4 , 1865 , May 12 , 1865 , May 26 , 1865 ( officially June 2 , 1865 ) and June 28 , 1865 , respectively .
Simplified: On June 23 , 1865 , Georgia 's Stand Watie became the last Confederate general to surrender .