If Petersburg fell, Richmond would fall too, and both Union General Grant and Confederate General Lee knew it. For nine and a half months from 1864-1865, Union and Confederate armies fought a brutal campaign at Petersburg that left the Confederacy on the verge of total defeat. In Virginia, the war changed here from a rapid succession of marches and battles into a methodical struggle of endurance and hardship. The Eastern Front spanned the entire siege, from the opening assaults in June 1864 to the blast at the Crater in July and Lee's last offensive at Fort Stedman in March 1865. The Western Front included fortifications and battle sites tied to Union efforts to cut Petersburg's supply lines, eventually stretching Confederate defenses to the breaking point. At Five Forks on April 1, 1865, the Union army defeated and captured nearly one-fifth of Lee's entire force, and Petersburg and Richmond fell two days later. During the siege, City Point became one of the busiest ports in America, and from his headquarters there Grant directed the movement of Union armies throughout the South. Converging rail lines made Petersburg the southern gateway to Richmond, and by the end of the siege more than 100 miles of earthworks scarred the landscape around the city.