The 12th Regiment, Vermont Volunteer Infantry (or 12th VVI) was a nine months' infantry regiment in the Union Army during the American Civil War. It served in the eastern theater, predominantly in the Defenses of Washington, from October 1862 to July 1863. It was a member of the 2nd Vermont Brigade.
The 12th Vermont Infantry, a nine months regiment, raised as a result of President Lincoln's call on August 4, 1862, for additional troops due to the disastrous results of the Peninsula Campaign.
It was composed of volunteers from ten volunteer militia companies as follows:
Colonel Asa P. Blunt, previously of the 3rd and 6th Vermont regiments, was selected to command the regiment. Lieutenant Colonel Roswell Farnham and Major Levi G. Kingsley had held commissions in the 1st Vermont Infantry, along with a total of 65 officers and men.
The regiment went into camp at Brattleboro on September 25, 1862, and was mustered into United States service on October 4. It left Vermont on October 7, and arrived in Washington, D.C. on October 10, and went into camp on East Capital Hill. On October 30 it became part of the 2nd Vermont Brigade, which also included the 13th, 14th, 15th and 16th Vermont Infantry regiments.
Colonel Blunt, as ranking colonel, commanded the brigade until the arrival of Brigadier General Edwin H. Stoughton, on December 7.
Stoughton was not popular with the officers and men of the brigade, so when he was captured by Confederate partisan John S. Mosby on March 9, 1863, few mourned his loss. Colonel Blunt assumed command of the brigade again, turning it over to the new brigade commander, Brigadier General George J. Stannard, on April 20, who led the brigade until the Battle of Gettysburg.