After Union Gen. Ulysses S. Grant's forces broke through Confederate Gen. Robert E. Lee's lines at Petersburg on April 2, 1865, Lee evacuated Petersburg and Richmond and retreated west with the Army of Northern Virginia while Grant pursued and kept part of the Federal force south of Lee to block his plan to join Gen. Joseph E. Johnston in North Carolina. On the morning of April 9, 1865, the last cavalry clash of the war in Virginia took place around the 1842 brick house of the widow Elizabeth S. Robertson near Appomattox Court House, where casualties were treated afterward. Confederate Gens. Thomas L. Rosser's and Thomas T. Munford's cavalry divisions, numbering 2,400 men, escaped the closing Federal encirclement of Lee's army and rode two miles west to the Richmond-Lynchburg Stage Road. Federal cavalry under Union Gen. Henry E. Davies's brigade charged as the Confederates reached the road at about 11 A.M.; the Federals briefly drove the 1st and 2nd Virginia Cavalry west but were soon repulsed. A second charge by Union Col. Samuel Young's brigade was pushed back to the Robertson House by the 1st Maryland Cavalry (CSA) and the rest of Col. William Wooldridge's brigade with 500 men of the 1st, 2nd, 3rd, and 4th Virginia Cavalry. Some Union troopers fired from the house's windows until Union Gen. Ranald S. Mackenzie arrived with reinforcements. At about noon, before another Federal attack, news arrived that Lee and Grant had agreed to a truce to discuss Lee's surrender, and Federal officers rode out under a white flag to inform the Confederate commanders. Munford chose not to surrender and withdrew his division to Lynchburg, where he disbanded it, while Lee surrendered later that day at Appomattox Court House.