As the South ran out of manpower the issue of arming the slaves became paramount. Lee explained, "We should employ them without delay ... [along with] gradual and general emancipation". The first units were in training as the war ended. As the Confederate army was devastated by casualties, disease and desertion, the Union attack on Petersburg succeeded on April 2, 1865. Lee abandoned Richmond and retreated west. Lee then made an attempt to escape to the southwest and join up with Joseph E. Johnston's Army of Tennessee in North Carolina. However, his forces were soon surrounded and he surrendered them to Grant on April 9, 1865, at the Battle of Appomattox Court House. Other Confederate armies followed suit and the war ended. The day after his surrender, Lee issued his Farewell Address to his army.