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Many major battles of the American Civil War were fought in Tennessee—most of them Union victories. Ulysses S. Grant and the U.S. Navy captured control of the Cumberland and Tennessee rivers in February 1862. They held off the Confederate counterattack at Shiloh in April. Memphis fell to the Union in June, following a naval battle on the Mississippi River in front of the city. The Capture of Memphis and Nashville gave the Union control of the western and middle sections; this control was confirmed at the Battle of Murfreesboro in early January 1863 and by the subsequent Tullahoma Campaign.

Which Union commander seized control of the Tennessee River in February 1862?
Ulysses S. Grant