Battle of Port Hudson
At Port Hudson confederate forces were attacked and besieged by union naval and army forces. after a month of siege a relief force of about 35,000 troops under general Robert Turner attacked union forces which numbered 42,000 men after several flank movements an engagement that lasted 4 hours ended with 19,500 union casualties. About 4,500 union troops became prisoners of war and sent to Andersonville where about only 1,000 survived the war.