Answer:
Grant was among the few experienced officers available when the American Civil War started in 1861. He was tasked by the governor of Illinois with turning the unruly Twenty-First Illinois Volunteer Infantry Regiment into a disciplined combat force. The volunteers quickly came to appreciate Lieutenant Colonel Grant after he disciplined the men and conducted drills with them. His achievements were recognized by the Army, which elevated him to brigadier general. As he commanded his men to engage in battle and triumph in the Western Theater, Grant attracted notice. In Tennessee, he overran Fort Henry and Fort Donelson, compelled Vicksburg, Mississippi, to submit, and at Chattanooga, Tennessee, he routed a larger Southern force. He received praise and criticism for his willingness to battle and take a lot of fatalities in the final year of the war. By ordering the Union forces to occupy General Robert E. Lee's Army of Northern Virginia at Petersburg, a small city south of Richmond, Virginia, and force its surrender in April 1865, Grant contributed to bringing the terrible Civil War to a conclusion. General Grant was the most admired person in the Union at that time.