1st Missouri Infantry Regiment (Union)

1st Missouri Infantry Regiment (Union)
Unit name	1st Missouri Infantry Regiment (Union)
Dates	June 1861 – July 1865
Country	United States
Allegiance	Union
Branch	Army
Type	Infantry
Size	Regiment

1st Missouri Infantry Regiment (Union) The 1st Missouri Infantry Regiment (Union) was a volunteer infantry regiment raised in Missouri for Federal service during the American Civil War. Organized in St. Louis in 1861, the regiment served in multiple campaigns in the Western Theater and on garrison duty, participating in actions across Missouri, Arkansas, Louisiana, and the Department of the Gulf. Its service included operations tied to major events such as the Camp Jackson affair, the Vicksburg Campaign, and the Red River Campaign.

Formation and Organization

The regiment was mustered into Federal service in June 1861 under authority of President Abraham Lincoln and the War Department, responding to calls following the Missouri Secession Crisis and the Camp Jackson affair. Recruitment drew volunteers from St. Louis, Jefferson City, Franklin County, St. Charles County, and surrounding counties, with enlistments processed through Camp Jackson and Lyon's Depot. Early organization involved coordination with the Department of the West, the Western District of Missouri, and Unionist political leaders including Francis P. Blair Jr. and Nathaniel Lyon. Muster rolls, company designations, and regimental staff were established in conformity with Regular Army practice, and the regiment received orders from commanders such as Brigadier General William S. Harney and later Brigadier General Henry Halleck during initial organization and deployment.

Service History

After muster, the regiment performed garrison and provost duties in St. Louis before moving to field service attached to Major General John C. Frémont's command in the Department of the West. It operated in counterinsurgency and security roles during the Missouri campaign seasons of 1861–1862, engaging Confederate irregulars and Missouri State Guard elements linked to Sterling Price. Assigned to the Army of the Tennessee and later to commands under Major General William T. Sherman and Major General Ulysses S. Grant, the unit participated in riverine and land operations, including expeditions on the Mississippi River, the Arkansas River, and operations around Vicksburg. Elements of the regiment were detached for service in the Department of the Gulf during occupation of New Orleans and operations in Louisiana. Throughout 1863–1864 the regiment rotated between field campaigns, garrison duty at Port Hudson, and engagements during the Red River Campaign under Major General Nathaniel P. Banks. In 1865 the regiment performed occupation service during the closing months of the war and was mustered out in July 1865 following orders from the Adjutant General of the Army.

Engagements and Battles

The regiment’s combat and operational record included actions at or near Camp Jackson affair, skirmishes with Missouri State Guard units under Sterling Price, and confrontations related to the Wilson's Creek theater. It supported Union naval operations during operations against Vicksburg, participated in assaults and siege operations linked to the Siege of Vicksburg, and saw action during the Red River Campaign including maneuvers near Monett's Ferry and Mansfield-area operations. The unit was involved in counter-guerrilla patrols in Missouri and military policing during the Occupation of New Orleans. It also took part in expeditions against Confederate supply lines associated with the Trans-Mississippi Theater and in actions overlapping with operations by the Western Theater commands.

Casualties and Strength

Initial regimental strength on muster approached typical Union volunteer regiment complements, with authorized strength around ten companies and roughly 800 men. Attrition from battle, disease, and reenlistments reduced effective strength over successive campaigns. The regiment sustained combat casualties during clashes with Missouri State Guard forces and in operations around Vicksburg and the Red River Campaign, while disease—common in Civil War camps such as those at Camp Jackson, Port Hudson, and riverine encampments—caused significant non-combat losses. The regiment’s final muster-out rolls reflect reductions due to wounds, prisoner of war losses during captures or paroles, transfers to Veteran Reserve Corps, and expiration of enlistments.

Commanders

Senior officers who led the regiment included colonels and field officers appointed from Missouri Unionist circles and regular army transfers; leadership interacted with commanders such as Nathaniel Lyon, John C. Frémont, Henry Halleck, Ulysses S. Grant, William T. Sherman, and theater-level leaders including Nathaniel P. Banks. Company officers drew from local elites in St. Louis, Jefferson City, and Franklin County, with noncommissioned officers promoted from the ranks during siege operations and garrison duty. Regimental command changed with promotions, casualties, and reassignments under Adjutant General of Missouri administration.

Equipment and Uniforms

The regiment was equipped with standard Union small arms of the period, including variants of the Springfield Model 1861, assorted Pattern 1853 Enfield imports, and captured or locally procured arms common in Western Theater units. Sidearms and edged weapons were service pistols and bayonets issued under Ordnance Department supply. Uniforms followed United States Army uniform patterns for volunteer infantry—dark blue frock coats, sky-blue forage caps or kepi-style headgear, and lighter sky-blue trousers—subject to variation from volunteer supply through Sanitary Commission assistance and quartermaster procurement at depots such as St. Louis Arsenal.

Legacy and Commemoration

The regiment's service is commemorated in Missouri military histories, regimental rosters, and Civil War Centennial retrospectives highlighting Unionist efforts during the Missouri Secession Crisis. Veterans joined organizations such as the Grand Army of the Republic and contributed to monuments and memorialization in St. Louis, Jefferson City, and battlefield markers near Vicksburg National Military Park and sites in Louisiana. Records and muster rolls are preserved among collections at institutions including the Missouri Historical Society, the Library of Congress, and state archives, informing scholarly work on American Civil War historiography, Union operations in the Trans-Mississippi Theater, and Missouri’s wartime experience. Category:Units and formations of the Union Army from Missouri