 He again led a division at Knoxville and during Lt. Gen. Ulysses S. Grant's Overland Campaign.On December 12, 1864, President Abraham Lincoln nominated Willcox for appointment to the brevet grade of major general of volunteers to rank from August 1, 1864, and the U.S. Senate confirmed the appointment on April 14, 1865.Following the Siege of Petersburg, he led the first troops to enter Petersburg, Virginia, before ending the war serving in North Carolina.