Authorized May 4, 1861 by direction of the President & confirmed by Act of Congress, July 29, 1861.

Recruited from: Pennsylvania, Ohio, and New York.

Date of organization: Sept. 12, 1861 (Companies B, D, E, F, G, H, I, & K)

Company A added October 15, Company M on November 1, Company C on November 23, and Company L on July 13, 1862

At the start of the Civil War, the United States Army had only five mounted regiments, the 1st and 2nd Dragoons, the 1st and Second US Cavalry, and the Regiment of Mounted Rifles. It was soon apparent that the war wasn't going to end after a few battles. In May of 1861, President Lincoln directed the addition of 1 regiment of cavalry, 1 of artillery, and 8 of infantry to the regular army. (Before the war's end, 272 regiments of cavalry, 232 batteries of artillery, and 1096 regiments of infantry would be called into battle.) On August 10, the Adjutant General's Office General Order No. 55 re-designated the regular army's mounted units as follows:

The 1st Dragoons - 1st US Cavalry

The 6th United States Cavalry, the only regular mounted unit formed during the Civil War, was organized at Pittsburgh PA and recruited from Pennsylvania, Ohio, and New York. Recruits, many of them being fresh immigrants right off the boat from Ireland, enlisted for five-year terms originally, with the enlistment term changed to three years when the unit was re-flagged as the 6th. The organization of the regiment followed the army's "new" model of three battalions, each with two squadrons, and each squadron formed of two companies. With an experienced cadre of Regulars assigned from the army's original mounted regiments, there was no election of officers or sergeants. Otherwise the regiment was recruited much the same as any other volunteer unit.

On September 12, the regiment mustered 607 men and moved to Bladensburg MD where it was mounted and equipped. By October 12, eight companies (B, D, E, F, G, H, I, and K) had been organized and marched to the Camp of Instruction, east of Washington DC. Sufficient recruits arrived to organize Company A on October 15, Company M and the regimental band on November 1, and Company C on December 23. (Company L did not join the regiment until July 13, 1862, near Harrison's Landing VA, after the Seven Days' Battles.)

Owing to the large number of volunteer units then being organized, carbines were in woefully short supply and all but one squadron of the regiment was initially equipped as Light Cavalry, with revolvers and sabers being their only weapons. Training progressed and by the end of October daily regimental and squadron drills were conducted in full marching order. The regiment continued to train and served in the defenses of Washington until March of 1862. Carbines were at last issued to the remaining squadrons and on March 10 they left the Capitol to participate in the Peninsula Campaign. The regiment received its baptism by fire on May 5 during the siege of Yorktown and would remain in the field for more than three years participating in all of the Army of the Potomac's campaigns. The regiment became known as the "Iron Brigade" at that time, for the fierce way in which they devoted themselves to the harshness of battle.

In February of 1863 the regiment was assigned to the Third "Reserve" Brigade of Brigadier General John Buford's 1st Cavalry Division. With the Reserve Brigade, the regiment saw action at Chancellorsville, participated in "Stoneman's Raid," and also fought at Brandy Station, Middleburg, and Upperville prior to the Battle of Gettysburg.

Under newly-promoted Brigadier General Wesley Merritt, the Reserve Brigade was assigned to screen the left flank and rear of the Union Army between Hagerstown and Frederick MD, and was actually not on the field during the Gettysburg battle's first two days. On the morning of July 3, however, a dispatch from Major General Alfred Pleasonton, Commander of the Cavalry Corps, arrived at Merritt's Emmitsburg HQ ordering him to move to Gettysburg and attack the Confederate right flank and rear. While on the march toward Gettysburg, Merritt ordered the 6th Cavalry, under the command of Major Samuel Henry "Paddy" Starr to Fairfield PA to seize a Confederate wagon train rumored to be foraging for supplies and food there. About eight miles west of Gettysburg, the mission to Fairfield would put the regiment in a position to cut off the Confederate line of retreat. The mission entailed significant risk, as the 6th would be operating well behind enemy lines, far beyond the support of the rest of the brigade. Compounding the danger, the regiment was under-strength, having had to previously detach a squadron for duty with General Pleasonton's headquarters.

Major Starr, a legendary Dragoon, was the most experienced officer in the Reserve Brigade. A 31-year veteran, he had enlisted as a private in 1832 and rose through the ranks. At the outbreak of the Civil War, Starr was a captain in the 2nd Cavalry. He was appointed as a Colonel of Volunteers and commanded the 5th New Jersey Volunteer Infantry, leading them in the battles of Williamsburg and Fair Oaks. Starr resigned from the Volunteers in October 1862, and returned to the Regular Army, being appointed Major of the 6th Cavalry in the spring of 1863. For a time he commanded the Reserve Brigade, but returned to command the regiment when the young Merritt was promoted.

Major Starr led his 400 troopers toward Fairfield without encountering any enemy resistance at all. South of the village he detached his 1st Squadron under Captain George Cram to follow a railroad bed and reconnoiter a wooded hillside to the west of the town, and from there to screen the regiment's left flank as it moved through the town and north along the Fairfield-Orrtanna Road. No Confederate wagon train was ever found, but a few wagons had apparently just left the town as the regiment was arriving. Starr immediately sent a squadron in pursuit under the command of Lieutenant Christian Balder.

Charging after the retreating wagons, Balder's squadron ran head-long into a large column of approaching Confederate cavalry. This was the 7th Virginia; the lead element of Confederate Brigadier General William E. "Grumble" Jones' brigade. Balder quickly wheeled his squadron around and raced back toward Fairfield to alert the rest of the regiment. Major Starr halted the regiment at the narrowest point in the valley and deployed for the impending fight, much in the same manner as King Leonidas deployed his Spartans against the Persian horde of King Xerxes at Thermopalyae. Stout post and rail fences lined the road, as well as an apple orchard on the left side and wheat fields on the right. Two squadrons dismounted and deployed along both sides of the road. Lieutenants Balder's and Bould's squadrons remained mounted along the road.

Without taking time to determine the strength of the Union position, Jones hastily ordered the 7th Virginia to charge forth. The Confederate horsemen were met by a deadly and effective hail of carbine fire from both flanks. Caught in a crossfire, hemmed in by the fences and blocked from moving forward, the badly mauled 7th Virginia quickly retreated back on down the road. Major Starr ordered a charge to pursue the retreating Virginians and continued to push them back. Jones, however, had brought an artillery battery into action and countered with a charge by the rest of his remaining brigade. The 6th Cavalry collided with the 6th Virginia, the 11th Virginia, and elements of the routed 7th Virginia. The fight quickly turned into a brutal hand-to-hand brawl and the badly out-numbered Federals lost with 242 troopers killed, wounded, or captured.

As the charging forces collided, the 6th Cavalry's standard bearer was shot. As the Confederates were about to seize the regiment's colors, Sergeant George C. Platt charged into the melee and wrested the standard from their grasp; which would have been a definite blow to the morale of the regiment. For his distinguished bravery, above and beyond the pale of normal duty, Platt was awarded the Medal of Honor.

During the Civil War, the regiment lost 8 officers and 53 men killed in action, 122 wounded in action, and 438 captured or missing (most of these during the Fairfield fight).

By the time of the May 1865 Grand Review in Washington, the 6th US Cavalry had earned battle honors in 60 engagements. Unlike the volunteer units that were all disbanded at the end of the war, the 6th Cavalry continued to serve with distinction in the regular army.

After the Civil War, the 6th Cavalry moved west, spending more than thirty years policing the frontier and participating in 10 Indian War Campaigns, facing many hostile tribes, including the Comanches and Apaches. This led to many Cavalry Troopers receiving the our nation's highest honor for bravery and valor, above and beyond the normal course of duty; that singular honor being the Congressional Medal of Honor.

In 1898, the 6th Cavalry Regiment sailed to Cuba, where it took part in the assault on San Juan Hill along with Teddy Roosevelt's "Rough Riders" of the 1st Volunteer Cavalry.

In 1900 and in 1907, the 6th Cavalry deployed to the Far East for 3-year tours. First the Cavalry went to China to participate in a 3-year relief expedition. Later, the 6th Cavalry posted its colors in the Philippines to defend our nation's interests. In 1909, the 6th Cavalry Regiment defeated the Moro tribe in a major battle on Jolo.

In 1910, the 6th Cavalry returned to the United States and took up duty patrolling the Mexican border. In 1916, 6th Cavalry was sent into Mexico as part of the Punitive Expedition in order to capture Pancho Villa.

In the spring of 1918, the 6th Cavalry Regiment deployed to France, serving in the rear echelon during World War I. After World War I, the 6th Cavalry returned to Fort Oglethorpe, Georgia where it remained until 1942.

In 1942, 6th Cavalry turned in the last of its horses and later reorganized as the 6th Cavalry Group, Mechanized, and the 6th and 28th Cavalry Reconnaissance Squadrons. In 1944, they again deployed to Europe to fight in World War II. 6th CAV participated in 5 campaigns in Europe. After the war, the 6th CAV performed occupation duties in Germany. In 1948, the unit was reorganized as the 6th Armored Cavalry.

The 6th ACR returned to Fort Knox, Kentucky in 1957 where it remained until 1963, when it was deactivated. In 1967, the Regiment reactivated at Fort Meade, Maryland, where it served for four years.

In June 1973, the Regiment was redesignated at the 6th Cavalry Brigade (Air Combat). 1st Squadron reorganized as an aviation unit under the 6th Cavalry Brigade (Air Combat). While at Hood, the brigade was a test bed for new concepts involving the use of attack helicopters on the modern battlefield. In 1980 C Troop was provisionally reactivated and assigned to Fort Rucker Alabama, where these concepts were tested during various ARTEPS, FTX's and other tactical exercises, until 17 January 1985 when it was reactivated as one of the premier AH-64 Apache Attack helicopter units in the United States Army.

In July 1996, the 6th Cavalry Brigade Headquarters and 3-6 Heavy Cav moved their flags from Fort Hood to Korea. 1-501 Attack Helicopter Battalion was reflagged as 1-6 Cav. In December 1996, 1st Battalion, 43d Air Defense Artillery was assigned to the brigade, giving the Brigade critical force protection assets.

Today, the 6th Cavalry Brigade consists of a BDE HQ at Camp Humphreys, 1-6 Cavalry Squadron (Fighting) at Camp Eagle, 3-6 Cavalry Squadron (Heavy Cav) at Camp Humphreys, and 1-43 Air Defense Artillery Battalion (Cobra) at Suwon AB, Osan AB, and Kunsan AB.