The 1st Missouri Volunteers evolved from one of several unofficial pro-Unionist Home Guards militia formed in St. Louis in the early months of 1861 by Congressman Francis Preston Blair, Jr.

Francis Preston Blair, Jr.

Francis Preston Blair, Jr. was an American politician and Union Army general during the American Civil War. He represented Missouri in both the House of Representatives and the Senate, and he was the Democratic Party's nominee for Vice President in 1868.-Early life and career:Blair was born in...

 and other Unionist activists. The militia that would become the First Missouri was largely composed of ethnic Germans, although Companies K and I had significant numbers of native born American citizens and Irish-Americans. Although initially without any official standing, beginning on April 22, 1861 four militia companies Blair helped organize were sworn into Federal service by Captain John Schofield

John Schofield

John McAllister Schofield was an American soldier who held major commands during the American Civil War. He later served as U.S. Secretary of War and Commanding General of the United States Army.-Early life:...

 acting on the authority of President Lincoln.

The 1st Missouri Volunteer Infantry elected Congressman Blair colonel of the regiment. The five militia companies, also elected (then) Captain Nathaniel Lyon

Nathaniel Lyon

Nathaniel Lyon was the first Union general to be killed in the American Civil War and is noted for his actions in the state of Missouri at the beginning of the conflict....

 as the brigadier general of the new brigade of Missouri volunteers. President Lincoln would later confirm Lyon's promotion from Captain to Brigadier general.

Military Service

On May 10, 1861 the 1st Missouri under Colonel Blair participated in the arrest of the Missouri Volunteer Militia drilling at Camp Jackson at Lindell Grove on the western border of St. Louis City. As the Missouri militiamen were being march under guard back to the Arsenal near the riverfront, angry crowds confronted the Federal forces and the confused situation soon devolved into rioting and gunfire. Over 27 people were killed and the Camp Jackson Affair helped to polarize the state and send Missouri down the road to its own internal civil war.

After the collapse of a truce negotiated by Federal Brigadier General William S. Harney

William S. Harney

William Selby Harney was a cavalry officer in the U.S. Army during the Mexican-American War and the Indian Wars. He was born in what is today part of Nashville, Tennessee but at the time was known as Haysborough....

 and Missouri State Guard

Missouri State Guard

The Missouri State Guard was a state militia organized in the state of Missouri during the early days of the American Civil War. While not initially a formal part of the Confederate States Army, the State Guard fought alongside Confederate troops and, at times, under regular Confederate...

 commander Sterling Price

Sterling Price

Sterling Price was a lawyer, planter, and politician from the U.S. state of Missouri, who served as the 11th Governor of the state from 1853 to 1857. He also served as a United States Army brigadier general during the Mexican-American War, and a Confederate Army major general in the American Civil...

, the 1st Missouri, along with other Federal forces were ordered by Lyon to move on the Missouri state capitol, at Jefferson City

Jefferson City, Missouri

Jefferson City is the capital of the U.S. state of Missouri and the county seat of Cole County. Located in Callaway and Cole counties, it is the principal city of the Jefferson City metropolitan area, which encompasses the entirety of both counties. As of the 2010 census, the population was 43,079...

. When the Federal forces arrived on June 15, the pro-secessionist Governor, Claiborne Fox Jackson

Claiborne Fox Jackson

Claiborne Fox Jackson was a lawyer, soldier, and Democratic politician from Missouri. He was the 15th Governor of Missouri in 1861, then governor-in-exile for the Confederacy during the American Civil War.-Early life:...

 had already abandoned the city and Brigadier General Lyon's forces captured the city without resistance. Lyon then pursued Jackson and the State Guard to nearby Boonville

Boonville, Missouri

This page is about the city in Missouri. For other communities of the same name, see Boonville Boonville is a city in Cooper County, Missouri, USA. The population was 8,202 at the 2000 census. It is the county seat of Cooper County. The city was the site of a skirmish early in the American Civil...

 where the Federals defeated the state forces on June 17 in the short, one-sided Battle of Boonville

Battle of Boonville

The First Battle of Boonville was a minor skirmish of the American Civil War, occurring on June 17, 1861, near Boonville in Cooper County, Missouri. Although casualties were extremely light, the battle's strategic impact was far greater than one might assume from its limited nature...

. While the Battle of Boonville was small by later war standards, it had major strategic consequences, driving the pro-secessionist forces into the southern part of the state and securing the Missouri River valley and communications across the state for the Federal government.

The 1st Missouri continued to campaign with Lyon, marching southwest to Springfield, eventually confronting a united Confederate and Missouri State Guard force near Springfield. The resulting Battle of Wilson's Creek

Battle of Wilson's Creek

The Battle of Wilson's Creek, also known as the Battle of Oak Hills, was fought on August 10, 1861, near Springfield, Missouri, between Union forces and the Missouri State Guard, early in the American Civil War. It was the first major battle of the war west of the Mississippi River and is sometimes...

 fought ten miles south of the city on August 10, 1861 was a bloody affair, and the second costliest in American History up to that time. The 1st Missouri, now under Lieutenant Colonel Charles Andrews, fought with Lyon's detachment of the Federal force on Bloody Hill. Isolated and outnumbered after a second Federal element under Colonel Franz Sigel

Franz Sigel

Franz Sigel was a German military officer, revolutionist and immigrant to the United States who was a teacher, newspaperman, politician, and served as a Union major general in the American Civil War.-Early life:...

 was routed, the Federals on Bloody hill fought the Confederate forces to a stalemate. The battle ended only after General Lyon was killed leading the 1st Iowa Infantry against the Confederate right. As the senior U.S. Army regular officer present, command devolved to Major Samuel D. Sturgis

Samuel D. Sturgis

Samuel Davis Sturgis was an American military officer who served in the Mexican-American War, as a Union general in the American Civil War, and later in the Indian Wars.-Early life:...

. Concerned about his force's ammunition supply, Sturgis decided to withdraw towards Springfield.

The 1st Missouri withdrew to Springfield and then to Rolla. A significant portion of the units members reenlisted as three-year volunteers, retaining the designation as the 1st Missouri Infantry. The regiment was then converted into an artillery unit by order of Major General John C. Fremont

John C. Frémont

John Charles Frémont , was an American military officer, explorer, and the first candidate of the anti-slavery Republican Party for the office of President of the United States. During the 1840s, that era's penny press accorded Frémont the sobriquet The Pathfinder...

, Commander of the Department of the West

Department of the West

The Department of the West, later known as the Western Department, was a major command of the United States Army during the 19th century. It oversaw the military affairs in the country west of the Mississippi River to the borders of California and Oregon.-Organization:The Department was first...

. The resulting 1st Missouri Light Artillery would see action in most of the campaigns in the Western Theater.