23 Lists of military units and formations of the American Civil War

This is a list of units from the State of Alabama that fought in the U.S. Army during the American Civil War (1861–1865):1st Alabama Cavalry Regiment 1st Tennessee & Alabama Independent Vidette Cavalry 11th United States Colored Infantry Regiment 55th United States Colored Infantry Regiment 106th United States Colored Infantry Regiment 110th United States Colored Infantry Regiment 111th United States Colored Infantry Regiment

Like almost all Southern states during the American Civil War, Arkansas provided a number of units to fight for the Union organized from African-Americans and Northern sympathizers. Despite having the third smallest white population of any Confederate state, Arkansas supplied more troops for the Union army than any other Confederate state except Tennessee. A total of 5,526 African-Americans served in Union units raised from the State of Arkansas. The list of Confederate units is shown separately.

On April 12, 1861, South Carolina artillery opened fire on Fort Sumter to start the American Civil War. While many gold seekers in the Colorado Territory held sympathies for the Confederacy, the vast majority remained fiercely loyal to the Union cause. An infantry and two cavalry regiments, as well an artillery battery, were sent to the support Union operations; others were raised for internal defense.

List of military units raised by the state of Indiana during the American Civil War.

List of military units raised by the state of Kansas during the American Civil War (1861–1865).

This is a list of military units raised by the Commonwealth of Kentucky, a Union border state during the American Civil War, for service in the Union Army. Southern both geographically and culturally, an estimated 125,000 Kentuckians served as Union soldiers; almost quadruple the number of Kentuckians serving as Confederate soldiers. The list of Kentucky's Confederate Civil War units is shown separately.

This is a list of regiments from the U.S. state of Louisiana that fought in the Union Army during the American Civil War (1861–1865). The list of Louisiana Confederate Civil War units is shown separately.

List of military units raised by the state of Maine during the American Civil War.

This is a list of Civil War regiments from Maryland which fought in the Confederate States Army. The list of Maryland Union Civil War units is shown separately.

This is a list of Civil War regiments from Maryland which fought in the Union Army. The list of Maryland Confederate Civil War units is shown separately.

This article provides a list of Michigan military units active during the American Civil War. As a northern state, Michigan was part of the Union, and its units were active during the entire length of the war. Units included the Michigan Brigade, which served under George Armstrong Custer during the Gettysburg Campaign.

List of military units raised by the state of New Hampshire during the American Civil War.

This is a list of North Carolina Confederate Civil War units. The list of North Carolina Union Civil War regiments is shown separately.

As in almost all Southern states during the American Civil War, a number of units were raised to fight for the Union from pro-Union citizens and former slaves. North Carolina provided the Union Army with units at 25,000, the second-highest number of troops from a Confederate state to fight for the Union. Around 24,000 troops from Confederate North Carolina regiments also deserted and joined the Union, bringing the total to over 49,000. The 1st North Carolina Infantry was established in the spring of 1861, near the town of Warrenton. Union troops captured and raided cities and towns in western North Carolina, eastern Tennessee and southwest virginia, most notably during the Battle of Bull's Gap, Battle of Red Banks and Stoneman's 1864 and 1865 raid. The territory captured remained under Union control for the duration of the war. The list of North Carolina Confederate Civil War units is shown separately.

List of military units raised by the state of Rhode Island during the American Civil War.

This is a list of Tennessee Confederate Civil War units. The list of Tennessee Union Civil War units is shown separately.

This is a list of regiments from the state of Tennessee that fought in the Union Army during the American Civil War (1861-1865). The list of Tennessee Confederate Civil War units is shown separately. Although Tennessee was officially a Confederate state in the conflict, the state would furnish the Union with the most units from a Southern state than anywhere else in the Confederacy, totaling at 31,092.

List of military units raised by the state of Vermont during the American Civil War.

Virginia provided the following units to the Virginia Militia and the Provisional Army of the Confederate States (PACS) during the American Civil War. Despite the state's secession from the Union it would supply them with third most troops from a Southern state along with the newly created West Virginia totaling at 22,000. Also listed are the units of Virginian origin in the service of the Union Army.

West Virginia, which seceded from Virginia to join the Union, provided the following units to the Union Army during the American Civil War. Units raised in the western counties prior to the creation of the state of West Virginia were often known as "loyal Virginians" who formed the Restored government of Virginia in Wheeling, West Virginia in 1861, selecting Francis H. Pierpont as the new governor. The state produced the most highly-decorated cavalry regiment of the Union Army and was credited with 32,000 Union soldiers, including 10 Brigadier and Major Generals. The recent soldier count by the George Tyler Moore Center for the Study of the Civil War estimates West Virginia's soldiers to be around 20,000, the remaining soldiers consisting of large numbers of Pennsylvania and Ohio volunteers, and with re-enlistments credited as new soldiers.