The 1st New Hampshire Cavalry was officially detached from the 1st New England Cavalry January 7th 1864.
From October through December 1861 there were four companies of cavalry organized in Concord, New Hampshire. These companies were attached as a battalion to the 1st New England Cavalry as Companies I, K, L and M. The battalion was detached on January 7th 1864 and officially became the 1st New Hampshire Volunteer Cavalry. Under the command of Colonel John L Thompson they were ordered to Washington, DC April 23rd 1864. They were attached to the 2nd Brigade of the 3rd Division of the Army of the Shenandoah. A part of the regiment was in service at the Battle of Cold Harbor from June 1st to 12th 1864. They were involved in all of Union Philip H Sheridan’s Shenandoah Valley Campaign, including the Battle of Cedar Creek. They were on guard and patrol duty in the defenses of Washington, DC in March of 1863 against raids of Mosby’s Raiders.
During their service they had 33 men killed of mortally wounded, and 114 who died from disease. The 1st mustered out of service July 1865.