Sensing a weakness in the Confederate defenses around Richmond and Petersburg, Virginia, Union General Ulysses S. Grant seeks to break the siege of Petersburg by concentrating his force against one section of the Rebel trenches. However, Grant miscalculated, and the week-long operation at Deep Bottom Run that began on August 13 failed to penetrate the Confederate defenses.
Grant was operating on the information that General Robert E. Lee, commander of the Confederate Army of Northern Virginia, was sending part of his force to the Shenandoah Valley to support General Jubal Early, who had spent the summer fending off Union forces and threatening Washington, D.C. Without realizing that this information was false, Grant believed that a section of the Confederate trenches around Deep Bottom Run, between Richmond and Petersburg, was now lightly defended.
Grant shipped parts of three corps north across the James River on August 13. Led by General Winfield Scott Hancock, the plan called for a series of attacks along the Confederate fortifications. Beginning on August 14, the Yankees tried for six days to find a weakness. Although a Union force broke through at Fussell's Mill, a lack of reinforcements left the Federals vulnerable to a Confederate attack, and the Rebels quickly restored the broken line.
The campaign cost 3,000 Union casualties and about 1,500 for the Confederates. The Southern defensive network, stretching over 20 miles, remained intact, but the failed operation prevented Lee from shipping troops to Early in the Shenandoah; Early would soon face defeat at the hands of a larger Union force commanded by General Philip Sheridan.