[12] An incident between Colonel John H. McCunn and 1st Lieutenant Robert F. Hunter who was then serving with the provost guard.

McCunn was found guilty of conduct "prejudicial to the good order and military discipline" though also directed to "resume his sword and duties.

The regiment participated in the First Battle of Bull Run in MGEN McDowell's reserves and went into winter quarters near Bailey's cross-roads.

After several temporary assignments the regiment finally became a part of the 3d brigade, 1st division, III Corps in McClellan's Army of the Potomac (AoP) on March 13, 1862.

"[18] Amassing his army at Ft. Monroe, McClellan shelved his initial amphibious envelopment of Yorktown because the CSS Virginia was still in operation, and he ordered an advance up the Peninsula to begin April 4.

[19] On April 5, the IV Corps made initial contact with Confederate defensive works at Lee's Mill, an area McClellan expected to move through without resistance.

The men of the 37th had to endure frequent April rains that turned the opposing trenches to morasses of mud.

Escaped slaves entering the 37th's corps' lines on Saturday, May 3, reported that the Rebels were sending their supply wagons in the direction of Richmond.

Early Sunday morning, the 37th's corps commander, Heintzelman, ascended in one of Lowe's observation balloons and saw that the Yorktown defenses were empty.

It assaulted Ft Magruder, but by 15:00, was being driven back and was at the point of being overrun by MGEN James Longstreet when they were saved by the timely arrival of BGEN Philip Kearny's[note 8] 3rd Division.

The battle was heavy and fought where the gun smoke combined with rain and fog to hamper visibility.

[12] While McClellan reported this battle as a brilliant victory saved from defeat by his appearance on the field,[32] it was actually a planned delaying action by Johnston who bought time for his retreating army to get back to the defenses at Richmond.

McClellan, per usual, was inept when the enemy behaved differently from how he expected, and he downplayed the performance of his subordinates while puffing up his ineffective actions.

The regiment struck tents the morning of April 28 and marched about 6 miles toward the Rappahannock River where they encamped.

On May 3 while the brigade was moving to the rear of the Union lines, a deadly attack on the front and left flank caused confusion and forced the regiment to fall back.

[12] Attached to:[16][2][1][3] The official list of battles in which the regiment bore a part:[35][2][1][3] garrison at Fort Washington August, 1861, to March, 1862.)

[38] By the end of the first full year of hard campaigning, the regimented returned 720 Model 1842 smoothbore percussion muskets to the Adjutant General.