The Battle of Gettysburg: Pickett's Charge, by Peter Frederick Rothermel, 1870.

Peter Frederick Rothermel devoted almost five years to his monumental 16 by 32 foot painting of The Battle of Gettysburg: Pickett's Charge (1870). This canvas and other smaller Rothermel paintings of the battle are on display at the State Museum of Pennsylvania.
Credit: Courtesy of the State Museum of Pennsylvania, Pennsylvania Historical and Museum Commission