The Civil War history of the 3rd U.S. Cavalry regiment is largely unknown and unremarked. They were on the periphery of the conflict at its outbreak, and herculean efforts were involved simply to get them to the scene of large scale fighting by the end of 1862. Arguably, however, they had the most rigorous experience of any of the regular cavalry regiments during the war.

As with most Regular units, the Regiment of Mounted Rifles was caught off guard at the outbreak of the Civil War. Home to many seasoned veterans, the regiment had served on the frontier since the end of the Mexican War. Early 1861 found the regiment spread across New Mexico territory and portions of western Texas. They were renamed the 3rd U.S. Cavalry on August 3, 1861.

The regiment lost its commander prior to the outbreak of hostilities. Colonel William Wing Loring was born in Wilmington, North Carolina, and appointed to the Army from Florida. He was one of the original officers appointed to the regiment as a captain when it was created in 1846. He was wounded three times during the Mexican War, receiving two brevet promotions during the war and losing an arm to amputation. Despite the loss, he worked his way to command of the regiment. When promoted to colonel of the regiment on December 30, 1856 at the age of 38, he was the youngest colonel in the Army. He resigned his commission on May 13, 1861. In a conference in New Mexico prior to departing the regiment, he told his officers, “The South is my home, and I am going to throw up my commission and shall join the Southern Army, and each of you can do as you think best.”

Colonel Loring was succeeded by John S. Simonson. Simonson had also been appointed a captain when the regiment was formed in 1846, but his first service had come as a sergeant in the New York militia thirty years previously in 1814. He distinguished himself during fighting at Chapultepec during the Mexican War, but was far too old for active campaigning in the Civil War. He retired at his won request on September 28, 1861 “for incapacity resulting from long and faithful service, and from injuries and exposure in the line of duty.”

Newly promoted Lieutenant Colonel Marshall S. Howe of the 5th U.S. Cavalry was promoted to Colonel and command of the 3rd Cavalry, but he didn’t join the regiment until the following July. In the meantime, the regiment fought in numerous engagements during 1861.

First Lieutenant Christopher H. McNally led detachments of Companies B and F the regiment’s first engagement of the war. Another veteran, McNally worked his way through the ranks to first sergeant of Company D before his appointment to second lieutenant in 1855. He was promoted to first lieutenant in May 1861. This first fight against the Confederates didn’t go well for the mounted riflemen. In a fight at Mesilla, Texas on July 25, 1861, Lt McNally was wounded, and the squadron suffered “considerable loss.” They retreated to nearby Fort Fillmore.

Upon receiving word of the defeat, Major Lynde, the district commander, directed the abandonment of Fort Fillmore on July 26th. The following day he surrendered his entire command without warning at San Augustin Springs. Among the unwilling prisoners, were Lieutenants McNally and Alfred Gibbs and 88 men of Companies B, F and I. Soon receiving paroles, all of the regiment’s prisoners were assigned to Company F and sent to Fort Wayne, Michigan until they could be exchanged. By the time their exchange took place on August 27, 1862, their numbers had dwindled down to nearly nothing from discharge, desertion and death.

In the meantime, the remainder of the depleted regiment prepared for combat. Two new companies were authorized for the regiment in August 1861, but were not recruited. Of the 263 enlistments that expired during the year, only 61 soldiers re-enlisted. So few officers and troopers remained that Companies A, B, and H were “closed,” and the personnel reassigned to other companies. The regiment was now a reinforced battalion of Companies C, D, E, G, K and I, commanded by Major Benjamin S. Roberts.

A native of Vermont, Benjamin Roberts graduated from the U.S. Military Academy in 1835. He served as a lieutenant with the 1st Dragoons until 1839, when he resigned. Another original officer of the Mounted Rifles, he was appointed as a first lieutenant in 1846. Brevetted for gallant and meritorious conduct on three separate occasions during the Mexican War, he had been serving on the frontier with the regiment since the end of the war.

In September 1861, Captain Robert M. Morris defeated a force of Texans neat Fort Thorn with Companies C, G and K. Company E, consolidated from the squadron of E and H, reached Fort Wise, Colorado Territory on August 30th, following the departure of the last two companies of the 4th U.S. Cavalry. Captain Alexander McRae’s Company I was drilling as a light battery of artillery to utilize the few available artillery pieces in the district.

The regiment spent the remainder of the year in patrolling and preparing for future operations. According to its annual return, regimental strength on December 31st was only 453 enlisted men, optimistically counting the paroled prisoners in Michigan as “detached service.”