The regiment was so nicknamed because the officers of the 20th were young Harvard graduates.

[2] Fogel et al's Union Army Data urban sample suggests perhaps as many as two-thirds of the regiment's enlisted were immigrants with Irish immigrants making up half of the regiment's total.

[4] Lander's Brigade, Stone's (Sedgwick's) Division, Army of the Potomac, to March, 1862.

Their baptism of fire occurred at Ball's Bluff on October 21, 1861.

[6] Other battles included the Seven Days, Antietam, Fredericksburg, Chancellorsville, Gettysburg, the Wilderness, Spotsylvania Court House, the Siege of Petersburg, and the Appomattox Campaign.