Final answer:
Ulysses S. Grant captured Fort Henry and Fort Donelson in Tennessee in February 1862, which were strategic to the Union's Western Theatre campaign during the Civil War.
Step-by-step explanation:
Capture of Forts by Ulysses S. Grant in February 1862
In February 1862, General Ulysses S. Grant captured Fort Henry and Fort Donelson which were located in Tennessee. These captures were critical to the Union's strategy in the Western Theatre of the Civil War. Control over these forts allowed the Union to exert pressure on Confederate forces in the west and paved the way for further advancements along key rivers, particularly the important Mississippi River.
The success at Fort Henry and Fort Donelson signified one of Grant's early military victories, bolstering his reputation and foreshadowing his persistent efforts leading to significant victories such as the Siege of Vicksburg. The latter was a crucial turning point in the war, cementing Grant's standing and contributing to the ultimate surrender of Confederate forces in 1865.