I've been reading recently about the much overlooked battle of Franklin, TN in 1864. Many similarities with Gettysburg including the Confederate attack across a large open plain. Somewhat ironic that Hood ordered the frontal assault at Franklin when he asked several times for permission to flank the Union position at Little Round Top. The casualties figures at Franklin are astounding. The participants, including veterans from many of the harshest battles, remembered it as the fiercest battle of the war. Unfortunate that it is largely ignored in comparison to Gettysburg.
From Stanley Horn - Army of Tennessee (he underestimates the losses at GB, but an interesting comparison):
The annals of war may long be searched for a parallel to the desperate valor of the charge of the Army of Tennessee at Franklin, a charge which has been called "the greatest drama in American history." Perhaps its only rival for macabre distinction would be Pickett's Charge at Gettysburg. A comparison of the two may be of interest. Pickett's total loss at Gettysburg was 1,354; at Franklin the Army of Tennessee lost over 6,000 dead and wounded. Pickett's charge was made after a volcanic artillery preparation of two hours had battered the defending line. Hood's army charged without any preparation. Pickett's charge was across an open space of perhaps a mile. The advance at Franklin was for two miles in the open, in full view of the enemy's works, and exposed to their fire. The defenders at Gettysburg were protected only by a stone wall. Schofield's men at Franklin had carefully constructed works, with trench and parapet. Pickett's charge was totally repulsed. The charge of Brown and Cleburne penetrated deep into the breastworks, to part of which they clung until the enemy retired. Pickett, once repelled, retired from the field. The Army of Tennessee renewed their charge, time after time. Pickett survived his charge unscathed. Cleburne was killed, and eleven other general officers were killed, wounded or captured. "Pickett's charge at Gettysburg" has come to be a synonym for unflinching courage in the raw. The slaughter-pen at Franklin even more deserves the gory honor.