21st Indiana Infantry Regiment / 1st Indiana Heavy Artillery in the American Civil War

Overview

The 21st Indiana Infantry Regiment (later redesignated as the 1st Indiana Heavy Artillery) was an infantry unit from Indiana that served in the Union Army during the American Civil War. Organized at Indianapolis and mustered into service on July 24, 1861, the regiment initially served as infantry before being converted to heavy artillery in February 1863. The unit was active in the Western and Gulf theaters, participating in several significant campaigns and battles.

This regiment is distinct from other Indiana infantry regiments and should not be confused with units of different service terms or designations.

Organization & Service

The 21st Indiana Infantry Regiment was organized at Indianapolis and mustered in on July 24, 1861. The regiment departed Indiana for Baltimore, Maryland, about a week after mustering. While stationed in Baltimore, it participated in General Lockwood’s expedition to the eastern shore of Virginia. In February 1862, the regiment moved to Newport News, Virginia, and soon after joined General Butler’s expedition to the Gulf. During the bombardment of Forts St. Philip and Jackson, the regiment was aboard the “Great Republic” off the mouth of the Southwest Pass. A portion of the regiment landed in the rear of Fort St. Philip, while the remainder advanced up the Mississippi River to New Orleans, becoming the first Union troops to land there.

After establishing camp at Algiers, the regiment captured several steamers on the Red River. On June 1, 1862, it landed at Baton Rouge and fought in the battle there on August 5, sustaining significant casualties. In September, the regiment engaged Texas Rangers at Des Allemands. From October 1862 to February 1863, it was stationed at Berwick Bay, with detachments serving on gunboats and engaging Confederate forces, including actions at Comet’s Bridge and the destruction of the ironclad Cotton. On November 29, 1862, Col. James W. McMillan was promoted to brigadier general, and Lt. Col. John A. Keith became colonel.

In February 1863, the regiment was converted to heavy artillery and redesignated as the 1st Indiana Heavy Artillery. Two additional companies were organized and attached later that year. Elements of the regiment participated in the Teche campaign and the second battle at Fort Bisland. Most of the regiment moved to Port Hudson and took part in the 42-day siege. Companies were also engaged at La Fourche Crossing and Brashear City, with Company F captured at the latter. In August 1863, three companies joined the Sabine Pass expedition. During the winter of 1863–1864, many members reenlisted and received furloughs.

In 1864, Companies G and H participated in the Red River expedition, while other companies were stationed at various points in the Department of the Gulf. Six batteries of the regiment took part in the investment of Mobile and the reduction of Forts Morgan, Gaines, and Spanish Fort in April 1865. After the end of active operations, the regiment’s batteries were assigned to garrison duties at Forts Morgan, Pickens, Barrancas, Baton Rouge, and other river defense positions. The regiment was mustered out on January 13, 1866.

Engagements & Campaigns

• Expedition to the Eastern Shore of Virginia (1861)
• Operations at Newport News (early 1862)
• Bombardment of Forts St. Philip and Jackson (April 1862)
• Capture of New Orleans (April 1862)
• Battle of Baton Rouge (August 5, 1862)
• Action at Des Allemands (September 1862)
• Berwick Bay operations (October 1862 – February 1863)
• Engagements with the ironclad Cotton and at Comet’s Bridge (late 1862 – early 1863)
• Teche Campaign and Second Battle of Fort Bisland (April 1863)
• Siege of Port Hudson (May–July 1863)
• Action at La Fourche Crossing (June 1863)
• Sabine Pass Expedition (August 1863)
• Red River Expedition (1864, select companies)
• Investment of Mobile and reduction of Forts Morgan, Gaines, and Spanish Fort (April 1865)

Casualties

The original strength of the regiment was 1,363. Gains by recruits totaled 1,332, with 448 reenlistments and 696 unassigned recruits, for a total of 3,839 men. Losses by death numbered 392; desertions, 228; and 200 men were unaccounted for. Detailed breakdowns of killed, wounded, and died of disease are not fully specified in available sources.

Field Officers & Commanders

• Colonel James W. McMillan
• Colonel John A. Keith
• Colonel Benjamin F. Hayes
• Lieutenant Colonel John A. Keith
• Lieutenant Colonel Benjamin F. Hayes
• Lieutenant Colonel William Roy
• Lieutenant Colonel James W. Connelly
• Major Benjamin F. Hayes
• Major William Roy
• Major James Grimsley
• Major Edward McLaflin
• Major John W. Day
• Major James W. Connelly
• Major Isaac C. Hendricks
• Major Samuel E. Armstrong

Regimental Roster

The complete roster of the 21st Indiana Infantry Regiment (1st Indiana Heavy Artillery), including officers and enlisted men, is available on the regiment’s roster page. This resource provides names, ranks, and additional service details valuable for genealogical and historical research.

To view the full roster, visit the 21st Indiana Infantry Regiment (1st Indiana Heavy Artillery) Roster page.

Sources & References

• Official Records of the Union and Confederate Armies, Series I, various volumes and parts (Baltimore, Gulf, and Department of the Gulf operations)
• Indiana Adjutant General’s Report
• Dyer, Frederick H., A Compendium of the War of the Rebellion
• Fox, William F., Regimental Losses in the American Civil War
• The Union Army, Federal Publishing Company, 1908, Volume 3