21st Infantry Regiment
Modern Era, United States, Infantry
The 21st Infantry Regiment traces its lineage to the post-Civil War Regular Army and built its reputation through frontier duty, the Indian Wars, and later overseas service in the Spanish-American and Philippine-American wars. Over time it became one of the long-serving line regiments of the Regular Army.
In the twentieth century the regiment served in major Pacific and Asian campaigns and became especially associated with the Army's fighting in World War II and Korea. Its battalions later carried the lineage into the Vietnam-era Army and then into the Pacific-centered force structure of the late Cold War and after.
Today the regiment survives through battalion lineage rather than a full regimental headquarters, but the 21st Infantry remains identified with the hard-service tradition of the old Regular Army and with modern combat service in the Pacific theater.
Battalion Page
The battalion subpage collects the regiment's battalion illustrations and additional historical entries with sources. Open the 21st Infantry Regiment Battalions page.
Division timeline, 1916–2026 · assignments, patches and deployments →