Richard Heron Anderson

Richard Heron Anderson (October 7, 1821 – June 26, 1879) was a career U.S. Army officer, fighting with distinction in the Mexican–American War. He also served as a Confederate general during the American Civil War, fighting in the Eastern Theater of the conflict and most notably during the 1864 Battle of Spotsylvania Court House
Anderson chose to follow his home state and the Confederate cause, and he resigned from the U.S. Army (accepted on March 3, 1861) to enter service with the Confederate Army
At the Battle of Gettysburg in July 1863, Anderson's division was third in line of march approaching the town from the west on July 1, so they arrived late and had little involvement in the start of the battle.
On July 2, the second day of battle, Anderson's division attacked near the Union center.
On July 3, Anderson's brigades participated in the waning minutes of Pickett's Charge
During the spring of 1864, at the Battle of the Wilderness, Longstreet was severely wounded and Anderson took command of the First Corps, leading it throughout the Overland Campaign.
When Longstreet returned from his convalescence on October 19, 1864, Lee created the new Fourth Corps, which Anderson led through the Siege of Petersburg and the retreat towards Appomattox Court House in 1865
https://en.wikipedia.org/wiki/Richard_H._Anderson