Crossing the Rapidan River on May 4, 1864, Grant sought to defeat Lee's army by quickly placing his forces between Lee and Richmond and inviting an open battle. Lee surprised Grant by attacking the larger Union army aggressively in the Battle of the Wilderness (May 5–7), resulting in heavy casualties on both sides. Unlike his predecessors in the Eastern Theater, however, Grant did not withdraw his army following this setback, but instead maneuvered to the southeast, resuming his attempt to interpose his forces between Lee and Richmond. Lee's army was able to get into position to block this movement. At the Battle of Spotsylvania Court House (May 8–21), Grant repeatedly attacked segments of the Confederate defensive line, hoping for a breakthrough, but the only results were again heavy losses for both sides.