The document summarizes two important early battles of the American Civil War: the Union capture of Forts Henry and Donelson in February 1862, and the clash of the ironclad warships CSS Virginia and USS Monitor in March 1862. The Union took control of the Tennessee and Cumberland Rivers by capturing Fort Henry and Fort Donelson. In the Battle of Hampton Roads, the Confederate ironclad CSS Virginia sank two wooden Union ships but was counter by the Union's ironclad USS Monitor, demonstrating the importance of ironclad warships.