The II Corps was prominent by reason of its longer and continuous service, larger organization, hardest fighting, and greatest number of casualties.

The II Corps also fought in nearly every battle in the main Eastern Theater, from the 1862 Peninsula Campaign to the Confederate surrender at Appomattox Court House.

In the Seven Days Battles, the II Corps was not engaged until Savage's Station when it held off Confederate general John B. Magruder's troops.

Israel Richardson's division spent the battle to the north engaged in a standoff with "Stonewall" Jackson's troops on opposite sides of White Oak Swamp; fighting here was limited to artillery dueling.

The II Corps spent the Northern Virginia Campaign in Washington, D.C., and did not participate in it except at the very end when it moved out to cover the retreat of Maj. Gen John Pope's army.

Nearly one-half of these casualties occurred in Sedgwick's 2nd Division, in its bloody and ill-planned advance on the Dunker church, an affair that was under Sumner's personal direction; this included units like the 34th New York Volunteer Infantry Regiment on the left flank of the division's 1st Brigade, as well as the 1st Minnesota Volunteer Infantry of later Gettysburg fame.

The Irish Brigade, of Richardson's 1st Division, also sustained a terrible loss in its fight at the "Bloody Lane", but, at the same time, inflicted a greater one on the enemy.

Gen Winfield Hancock, brought over from the VI Corps as the ranking brigadier general in the division, John C. Caldwell, was too inexperienced and junior for the position.

The loss of the corps at Fredericksburg exceeded that of any other in that battle, amounting to 412 killed, 3,214 wounded, and 488 missing, one-half of which fell on Hancock's Division in the unsuccessful assault on Marye's Heights.

At Chancellorsville, the principal part of the II Corps's fighting fell on Hancock's division, its skirmish line, under Colonel Nelson A.

Hancock and Gibbon were seriously wounded, while of the brigade commanders, Samuel K. Zook, Edward E. Cross, George L. Willard, and Eliakim Sherrill were killed.

Warren had distinguished himself at Gettysburg by his quick comprehension of the critical situation at Little Round Top, and by the energetic promptness with which he remedied the difficulty.

He was, subsequently, in command at the Battle of Bristoe Station, a II Corps affair, and one which was noticeable for the dash with which officers and men fought, together with the superior ability displayed by Warren himself.

In the Battle of the Wilderness, the corps lost 699 killed, 3,877 wounded, and 516 missing; total, 5,092, half of this loss falling on Birney's 3rd Division.

At the Battle of Spotsylvania Court House the II Corps again attained a glorious place in history by Hancock's brilliant and successful assault on the morning of May 12.

Actual battlefield casualties were light, however 1,700 men were taken prisoner by the Confederates, including several whole regiments, some of them, such as 15th Massachusetts, once elite outfits.

In November, 1864, Hancock was assigned to other duty, and Major General Andrew A. Humphreys, chief of staff to the Army of the Potomac, succeeded to his position.

In spite of homesickness and coming from Democratic homes and ethnic communities which did not favor expanding war aims to emancipation, soldiers of II Corps saw the fighting through, re-enlisting in 1863-4 and voting overwhelmingly for Abraham Lincoln in 1864.

Pride in unit featured prominently in post-war reunions, and on the 50th anniversary of Gettysburg Speaker of the House Champ Clark from Missouri referred to soldiers of II Corps as "those unconquerable boys in blue".