In late June 1864, Confederate General Robert E. Lee and the Army of Northern Virginia were engaged in a desperate defense of the city of Petersburg. Victory for Lee depended on a steady flow of supplies from the west, brought in by rail. To force Lee from Petersburg, Union Geneneral U. S. Grant planned to cut Southern supply lines. He ordered a cavalry raid west to tear up track and destroy railroad stations and bridges. On June 22, 1864, Union Generals James H. Wilson and August V. Kautz, commanding more than 5,000 cavalry troops and 16 pieces of artillery, left Petersburg to destroy track on the Richmond & Danville Railroad and to burn the Staunton River Bridge.