In the American Civil War the Home Guard or Home Guards were local militia raised from Union loyalists.
In Missouri after the start of the Civil War there were several competing organizations attempting to either take the state out of the Union or keep the state within it. Home Guard companies and regiments were raised by Union supporters, particularly German-Americans to oppose the secessionist leaning Missouri State Militia (later the Missouri State Guard and secessionist paramilitary Minutemen. Many of the Home Guard regiments were raised from pre-existing Wide Awakes, a paramilitary militia that was very active in St. Louis.
Once actual hostilities began in the state in June 1861, Union loyalists in areas outside of St. Louis were organized and mobilized by Brigadier General Nathaniel Lyon to oppose Governor Claiborne Jackson's Missouri State Guard which was forming at the same time. One of these regiments, the Benton County Home Guards, was defeated by a battalion of Missouri State Guards at the Battle of Cole Camp. 
In late 1861 and early 1862 the Home Guard were replaced by Unionist militia regiments including the new Missouri State Militia (Union) as well as the compulsory Enrolled Missouri Militia in July 1862 and the Provisional Enrolled Missouri Militia formed later.
Iowa Home Guard companies provided border defense along the Missouri border during the Civil War. During the Battle of Athens, Missouri, Iowa Home Guard companies on the other side of the Des Moines River protected the supply depots.
Union volunteer infantry regiments known as the Indian Home Guard were recruited from the Five Civilized Tribes in the Indian Territory. Although the tribal leadership had supported the Confederacy, many of the tribal members did not.
- Cole Camp Community, Here We Speak Low German, 1989, pages 181–189.