In May 1864, the 4th left Yorktown and took part in Brigadier General Benjamin F. Butler's operations on the south side of the James River and against Petersburg and Richmond, Virginia.

The regiment saw action in a skirmish at Bermuda Hundred on May 4 and served the rest of Butler's campaign at Spring Hill on the Appomattox River.

Three men of the regiment received the Medal of Honor for their actions at Chaffin's Farm: Christian Fleetwood, Alfred B. Hilton, and Charles Veale.

In March 1865, the 4th Regiment was reassigned to the X Corps and took part in General William Tecumseh Sherman's Carolinas Campaign.

With the end of the war at hand, the men of the 4th witnessed the surrender of Confederate General Joseph E. Johnston and his army at Bennett Place, North Carolina, on April 26, 1865.