On June 15, 1864, the Battle of Petersburg began as General Ulysses S. Grant assaulted the Confederate line at the important Southern rail center of Petersburg. An excerpt from the article:
"City of Petersburg, VA | Jun 15 - 18, 1864
Ulysses S. Grant’s assault on Robert E. Lee’s armies at Petersburg failed to capture the Confederacy’s vital supply center and resulted in the longest siege in American warfare.
How it ended
Although the Confederates held off the Federals in the Battle of Petersburg, Grant implemented a siege of the city that lasted for 292 days and ultimately cost the South the war.
In context
General Ulysses S. Grant’s inability to capture Richmond or destroy the Confederate Army of Northern Virginia during the Overland Campaign (May 4–June 12, 1864) caused him to cast his glance toward the critical southern city of Petersburg. His strategic goals shifted from the defeat of Robert E. Lee's army in the field to eliminating the supply and communication routes to the Confederate capital at Richmond.
The city of Petersburg, 24 miles south of Richmond, was the junction point of five railroads that supplied the entire upper James River region. Capturing this important transportation hub would isolate the Confederate capital and force Gen. Robert E. Lee to either evacuate Richmond or fight the numerically superior Grant on open ground.
From June 15–18, 1864, Confederate general Beauregard and his troops, though outnumbered by the Federals, saved Petersburg from Union capture. The late appearance of Lee’s men ended the Federals’ hopes of taking the city by storm and ensured a lengthy siege. For the next nine months, Grant focused on severing Petersburg’s many wagon and rail connections to the south and west. He eventually attacked and crippled Lee’s forces, forcing the South to surrender at Appomattox on April 9, 1865."