On 8 September 1847, as US forces continued the drive to Mexico City, intelligence was received that a cannon foundry and a large supply of gunpowder was believed to be at Molino del Rey, 1,000 yards east of Chapultepec Castle.

The Regiment of Mounted Riflemen earned a reputation among Army leaders as a brave and tough unit; General Winfield Scott said "Where bloody work was to be done, 'the Rifles' was the cry, and there they were.

Fort Union became their home base, and the regiment's companies were spread out across a vast area stretching from Denver, Colorado, to the Mexico–United States border, and from West Texas to Nevada, Arizona, and Utah.

Service in New Mexico was constant and most exacting, and the various companies of the 1st Mounted Rifles were widely scattered and the number of troops available was wholly inadequate for the task of patrolling such a large area.

During the fighting, an officer from E Company, 3rd Cavalry, CPT Alexander McRae, commanded a battery of artillery and inflicted heavy damage upon the attacking enemy, but were eventually charged and destroyed.

[2] In April 1898, the regiment was assembled at Camp George H. Thomas in Chickamauga National Park and assigned to a brigade in a provisional cavalry division when the Spanish–American War erupted.

On 23 July, 1LT John W. Heard, the regimental quartermaster, was directing several troopers unloading supplies from the Wanderer near Bahia Honda when they were set upon by a force of 1,000 Spanish cavalrymen.

On 17 March 1917, the entire 3rd Cavalry Regiment was transferred to Fort Sam Houston, Texas, and one month later, the United States of America entered the First World War on the side of the Allies.

The occupation forces' first order of business was to continue training and to be prepared to implement a contingency plan in case Germany refused to sign the armistice or hostilities were resumed.

At Camp Gordon, Georgia the Group began conducting mechanized operations and participated in combined arms maneuvers in Tennessee and Fort Jackson, South Carolina before sailing to England.

[22] On 31 August 1944, the 1st platoon of B Troop, 3rd Cavalry Reconnaissance Squadron, with 30 men, 6 Jeeps armed with .50 cal MG, and three M-8 armored cars with 37 mm guns made a raid behind enemy lines to Thionville, France, in a desperate attempt to prevent the bridge across the Moselle from being destroyed by the Germans.

The platoon conducted the raid 75 miles (121 km) behind enemy lines as US Forces advanced slowly towards the Moselle River to effect a crossing on its push toward the German "West Wall".

Troop commander Captain James D. Jackson succeeded in crossing the river to the eastern approach to the bridge and cut the wires leading to the demolition charges, and was wounded in the attempt.

After VE Day, the troopers were ordered to cross the Alps into Northern Italy to keep an eye on the various factions vying for power in postwar Yugoslavia, but returned to Austria shortly afterwards.

Composed of Tiger Squadron and all regimental units remaining at Fort Carson, TFR was tasked with post red cycle duties as well as maintaining the many vehicles that were not taken to Bosnia.

Tiger Squadron conducted a Level I gunnery and a Combined Arms Live Fire Exercise before preparing to receive regimental units returning from Bosnia.

[30] The first elements of the regiment crossed the border into Iraq on 25 April 2003 and were immediately tasked to perform an economy of force mission to secure and stabilize Al Anbar Governorate in the western part of the country.

Killing or capturing former regime loyalists, securing mass grave sites, as well as restoring law and order by assisting Iraqi National Police was also accomplished by TF Rifles.

The 3rd ACR was focused on securing weapons caches between Lake Tharthar and the Euphrates River, and managed to detain several high-value targets on the Defense Intelligence Agency blacklist.

[31] Various units of the Task Force found themselves managing a large number of projects to rebuild the infrastructure and restore basic services, efforts aimed at winning the hearts and minds of the Iraqi people.

Shortly after entering Iraq, the 2nd Squadron of the 3rd ACR was tasked with protecting several abandoned enemy ammunition supply points (ASP) and the Air force base located in Al Habbaniyah.

The 3rd ACR began training for another tour in OIF right away, fielding new weapons systems (including new M1A2 Abrams tanks and M3A3 Bradley fighting vehicles) and re-build the organization following the move from Fort Carson.

Sabre Squadron, the installation's designated crisis reaction battalion at the time of the incident, was alerted to deploy back from training in the field and assist Fort Hood Emergency Services with cordoning the crime scene while the police searched for additional suspects.

Joined by Soldiers from Tiger, Thunder, and Muleskinner, Sabre Squadron manned entry control points around the post to systematically search vehicles leaving the installation later that evening and the continued to secure the gates for several days after the attack.

When President Obama visited Fort Hood on 10 November to help memorialize the twelve soldiers and one civilian who died in the attack, the regiment teamed with the Directorate of Emergency Services again to secure the route for the official convoy from the airfield to the III Corps headquarters.

After a short block leave for the winter holidays, the regiment's troopers began to prepare in earnest for what would likely be the 3rd ACR's last heavy stabilized gunnery beginning at the end of January.

On 30 Sep 2010 the regiment conducted a transition of authority with 3rd BDE, 3rd ID and assumed responsibility for the five northern provinces of United States Division-South under MG Vincent Brooks and the 1st Infantry Division.

At the same time as the main body of the 3rd Cavalry would deploy to Afghanistan, 4th Squadron joined 13 other states forming part of the Multinational Force and Observers (MFO) in the Sinai Peninsula.

[39] 3rd Cavalry Regiment supported the operation by working and training with Iraqi Security Forces and coalition partners to defeat ISIS in designated areas of Iraq and Syria.

Both Broadwater and Kenny were suspended from their duties, pending a final investigation of the 1st Cavalry Division's command climate and program for preventing and responding to sexual harassment and assault.