Answer: This was from Wikipedia because I never read this.
Step-by-step explanation:
"The Battle of Fort Henry was fought on February 6, 1862, in Donelson, Stewart County, Tennessee, during the American Civil War. It was the first important victory for the Union and Brig. Gen. Ulysses S. Grant in the Western Theater."
"On February 4 and 5, Grant landed two divisions just north of Fort Henry on the Tennessee River. (The troops serving under Grant were the nucleus of the Union's successful Army of the Tennessee, although that name was not yet in use.[3]) Grant's plan was to advance upon the fort on February 6 while it was being simultaneously attacked by Union gunboats commanded by Flag Officer Andrew Hull Foote. A combination of accurate and effective naval gunfire, heavy rain, and the poor siting of the fort, nearly inundated by rising river waters, caused its commander, Brig. Gen. Lloyd Tilghman, to surrender to Foote before the Union Army arrived."
"The surrender of Fort Henry opened the Tennessee River to Union traffic south of the Alabama border. In the days following the fort's surrender, from February 6 through February 12, Union raids used ironclad boats to destroy Confederate shipping and railroad bridges along the river. On February 12, Grant's army proceeded overland 12 miles (19 km) to engage with Confederate troops in the Battle of Fort Donelson."