On May 15, General Franz Sigel, a Union leader, decided to capture Staunton in order to ruin the communication system there which Lee had used to be kept informed about activities in the Shenandoah Valley. He arrived as far as New Market, in Shenandoah County, when he met Confederate General John C. Breckinridge who had a comparatively small army consisting mostly of young Virginia Military Institute cadets. They showed the benefits of their military training and successfully captured a Union battery. After this had been done, General Breckinridge advanced, defeated Sigel and drove him down the Shenandoah Valley. On May 23-27, 1864, the North Anna River in Hanover County became the next area of military concentration. General Lee and General Grant were on opposite sides of the river. Although the forces led by Grant were able to cross the river at various intervals, they were unable to penetrate the forces led by Lee. Consequently, Grant turned southwest and proceeded to march to Cold Harbor, approximately ten miles north of Richmond. When Grant arrived at Cold Harbor, he decided to have an all-out offensive against the forces of Lee at this location. His attempt was in vain, however, and he received very heavy losses on June 3. This caused him to retreat to the James River south of Richmond. On June 11, 1864 there was an important cavalry battle at Trevillians Station, in Louisa County, between Union General Philip Sheridan and Confederate cavalrymen led by Wade Hampton and Fitzhugh Lee. Sheridan had been trying to reach Union General Hunter who was on his way to Lynchburg. After heavy fighting on both sides, Sheridan was defeated and retreated eastward.