3rd Massachusetts Cavalry Regiment  The 3rd Massachusetts Volunteer Cavalry Regiment was a cavalry regiment that served in the Union Army during the American Civil War. It was organized by consolidating the 41st Massachusetts Mounted Infantry and the 2nd Battalion Massachusetts Cavalry on June 17, 1863. The regiment served with the XIX Corps, Army of the Gulf during the Red River Campaign in 1864. Its heaviest combat during this campaign took place during the Battle of Sabine Crossroads. On June 25, 1864, the unit was dismounted and ordered to serve as infantry. They were sent north on July 15 with other units of the XIX Corps to become part of the Army of the Shenandoah and served as infantry in several large battles during the Valley Campaigns of 1864. The regiment took significant casualties during the Third Battle of Winchester and the Battle of Cedar Creek. In February 1865, the unit was remounted again as cavalry and served in the Shenandoah Valley until the end of the war. The companies that had been the 2nd Battalion reached the end of their term of service in December 1864 and January 1865 and were replaced with two new companies consisting of Massachusetts recruits. The bulk of the regiment that had enlisted as the 41st Massachusetts were mustered out on May 20, 1865. What remained of the regiment took part in the Grand Review of the Armies in Washington, D.C. and then were deployed to Fort Leavenworth, Kansas. After serving in Kansas and Nebraska, they were mustered out on September 28 and returned to Boston. The regiment was formed from troops already serving in the field in Louisiana on June 17, 1863 by Special Order No. 144, Department of the Gulf. The 41st Massachusetts retained their original company letter designations during the consolidation. The three companies of the 2nd Battalion Massachusetts Cavalry were assigned to the regiment as Companies L, M, and the third without a letter designation known as "Read's Company." The regiment was attached to 2nd Brigade, 4th Division, XIX Corps, Army of the Gulf. The 2nd Battalion consisted of three companies recruited and organized during the fall and winter of 1861-1862. The first two companies were recruited in Boston and were initially known as the 1st and 2nd companies of Massachusetts Mounted Rifle Rangers. Cavalry units so named were known for their marksmanship and expected to act as sharpshooters when dismounted. These companies, prior to being organized as a battalion, were also known as the 1st, 2nd, and 3rd Companies Unattached Cavalry.