The Union made many attempts to invade Richmond. In the Peninsula Campaign of 1862, General George McClellan moved up the James River, almost to the suburbs of the city, but was beaten back by Robert E. Lee in the Seven Days Battles. In 1864-5, General U.S. Grant laid siege to nearby Petersburg. By April 1865, the Confederate government realized the siege was almost over and abandoned the city lest they be captured. The retreating Confederates chose to burn military supplies rather than let them fall into Union hands; the resulting fire destroyed much of central Richmond.