United States Infantry

The Infantry Branch (also known as the "Regular Army," "Regulars," or "Queen of Battle") is a branch of the United States Army first established in 1775.

History

Ten companies of riflemen were authorized by a resolution of the United States Continental Congress on 14 June 1775. However, the oldest Regular Army infantry regiment, the 3rd Infantry Regiment, was constituted on 3 June 1784, as the First American Regiment.

18th century

On 3 March 1791, Congress added to the Army the United States 2nd Regiment of Infantry

• An Act of Congress on 16 July 1798 authorized twelve additional regiments of infantry.
• An Act of Congress on 11 January 1812 increased the Regular Army to 46 infantry and 4 rifle regiments
• An Act of Congress on 3 March 1815 reduced the Regular Army from the 46 infantry and 4 rifle regiments it fielded in the War of 1812 to a peacetime establishment of 8 infantry regiments, further reduced to 7 in 1821. The origins of the Army's current regimental numbering system dates from this act.

19th century

The Army organized into seven infantry regiments, 1821;

• 1st Infantry Regiment
• 2nd Infantry Regiment
• 3rd Infantry Regiment
• 4th Infantry Regiment
• 5th Infantry Regiment
• 6th Infantry Regiment
• 7th Infantry Regiment
• 8th Infantry Regiment (added in 1838)

Ten one-year regiments were authorized by an Act of Congress on 11 February 1847 because of the Mexican–American War, but only the 9th through 16th Infantry Regiments were activated; they did not re-form permanently until the 1850s and 1860s.

• 9th Infantry Regiment (United States) (added in 1855)
• 10th Infantry Regiment (United States) (added in 1855)

Civil War expansion to 19 regiments;

• 11th Infantry Regiment
• 12th Infantry Regiment
• 13th Infantry Regiment
• 14th Infantry Regiment
• 15th Infantry Regiment
• 16th Infantry Regiment
• 17th Infantry Regiment
• 18th Infantry Regiment
• 19th Infantry Regiment

In a major expansion under General Order 92, and an act of Congress in 1866, the 2nd and 3rd battalions of the existing 11th through 19th Infantry Regiments were expanded and designated as the 20th through 37th Infantry Regiments. Four new regiments (the 38th through 41st) were to be composed of black enlisted men, and the new 42nd through 45th Infantry Regiments for wounded veterans of the Civil War.

• 20th Infantry Regiment
• 21st Infantry Regiment
• 22nd Infantry Regiment
• 23rd Infantry Regiment
• 24th Infantry Regiment
• 25th Infantry Regiment

This was reduced by consolidation to 25 regiments under General Order 17, War Department, 15 March 1869, with the 24th and 25th Infantry Regiments constituting the black enlisted force. On 2 February 1901, Congress passed the Army Reorganization Act, which authorized five additional regiments, the 26th through 30th;