 His brigade was later transferred to the command of Maj. Gen. John Pope and cited for bravery in leading a bayonet charge against Confederate forces of Stonewall Jackson at the Second Battle of Bull Run.Grover was transferred to the Department of the Gulf in December 1862 and commanded a division in the XIX Corps during the capture of Baton Rouge and the Siege of Port Hudson.Returning to the East in August 1864, he participated in the Third Battle of Winchester, Fisher's Hill, and Cedar Creek, where he was wounded and brevetted to the rank of major general of volunteers.