Infantry timelines · Infantry numbers 1–200

3d Infantry Regiment

A century of division assignments

1916–2026 · Regimental service, battle groups, battalions and deployments.

3d Infantry Regiment unit graphic
3d Infantry Regiment
First division shown7th Infantry Division24 Mar 1923
Separate battalion histories3 documented elementsDated lineages and service notes below
Page cutoff8 September 2026Last-documented status is explicitly marked

One regiment, separate assignments

The common row follows the regiment. After its reorganization, battle groups and battalions could hold different assignments at the same time. A deployment or temporary attachment does not by itself change the assigned division. The common row closes on 1 Jul 1957; later service belongs to the separate element rows. Battalion rows follow headquarters lineages, often descended from lettered companies, rather than assuming that the old regimental battalions continued unchanged.

Division patches

7th Infantry Division6th Infantry Division2d Infantry Division23d Infantry Division (Americal)

Representative division patches. Patterns could change over time; an image does not imply that the exact version was worn throughout every period. Divisions without a verified asset remain identified by name.

The dated record

Division timeline

Battalion overview →

Deployments, operations and credited campaign service appear inside assignment cards. Award years establish credited service, not exact tour dates. Some service notes identify only company-sized elements. This is a sourced selection, not a complete movement log.

Assignment ends are exclusive: the next period starts on that date. *Striped final bars mean last documented, with later status unverified through the page cutoff. Unknown intervals are not treated as inactive.

  1. 1 Jan 1916 – 24 Mar 1923

    3d Infantry Regiment

    Assignment not established

    The available record does not establish a precise assignment throughout this interval. No division is inferred.

    Source

  2. 24 Mar 1923 – 15 Aug 1927

    3d Infantry Regiment

    7th Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  3. 15 Aug 1927 – 1 Oct 1933

    3d Infantry Regiment

    6th Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  4. 1 Oct 1933 – 16 Oct 1939

    3d Infantry Regiment

    7th Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  5. 16 Oct 1939 – 10 May 1941

    3d Infantry Regiment

    6th Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  6. 10 May 1941 – 20 Nov 1946

    3d Infantry Regiment

    No assigned division

    The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit.

    Source

    Deployments & overseas operations

    1. 1941-1943

      Newfoundland

      3d Infantry Regiment · Deployment / overseas operation

      The old 3d Battalion deployed in January 1941; the old 1st Battalion was activated there in February 1942. These were regimental elements, not a simultaneous deployment of the entire regiment. More than one assignment falls in the opening year; this year-level service marker does not establish the assignment on a particular deployment day.

      Source

    2. 1945

      France and Germany

      3d Infantry Regiment · Deployment / overseas operation

      Arrived in France in March and served attached to the 106th Infantry Division around St. Nazaire before moving to Germany. This was an operational attachment.

      Source
  7. 20 Nov 1946 – 6 Apr 1948

    3d Infantry Regiment

    Inactive

    The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased.

    Source

  8. 6 Apr 1948 – 1 Jul 1957

    3d Infantry Regiment

    No assigned division

    The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit.

    Source

  9. 1 Jul 1957 – page cutoff*

    1st Battle Group / Battalion lineage

    Last documented: No assigned division

    The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit. The source establishes this last recorded status, not uninterrupted service through 2026. The striped bar extends to the page cutoff to keep the later research gap visible.

    Source

  10. 1 Jul 1957 – 1 Jul 1963

    2d Battle Group / Battalion lineage

    7th Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  11. 1 Jul 1963 – 1 Jun 1966

    2d Battle Group / Battalion lineage

    Inactive

    The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased.

    Source

  12. 1 Jun 1966 – 15 Oct 1970

    2d Battle Group / Battalion lineage

    199th Infantry Brigade · Separate

    This headquarters is not a division. Temporary attachments in the service entries below are distinct from the formal assignment.

    Source

    Deployments & overseas operations

    1. 1966-1970

      Vietnam

      2d Battle Group / Battalion lineage · Credited overseas service

      The Army lineage lists a unit decoration for service in these years. These are credited service years, not exact deployment and return dates. The labeled service overlaps an assignment change and is listed only once; consult the following assignment cards as well.

      Source
  13. 15 Oct 1970 – 16 Mar 2001

    2d Battle Group / Battalion lineage

    Inactive

    The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased.

    Source

  14. 16 Mar 2001 – 27 Jul 2005

    2d Battle Group / Battalion lineage

    2d Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

    Deployments & overseas operations

    1. 2003-2004

      Iraq

      2d Battle Group / Battalion lineage · Credited overseas service

      The Army lineage lists a unit decoration for service in these years. These are credited service years, not exact deployment and return dates.

      Source
  15. 27 Jul 2005 – 16 Sep 2015

    2d Battle Group / Battalion lineage

    2d Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

    Deployments & overseas operations

    1. 2006-2007

      Iraq

      2d Battle Group / Battalion lineage · Credited overseas service

      The Army lineage lists a unit decoration for service in these years. These are credited service years, not exact deployment and return dates.

      Source

    2. 2009-2010

      Iraq

      2d Battle Group / Battalion lineage · Credited overseas service

      The Army lineage lists a unit decoration for service in these years. These are credited service years, not exact deployment and return dates.

      Source

    3. 2011-2012

      Afghanistan

      2d Battle Group / Battalion lineage · Credited overseas service

      The Army lineage lists a unit decoration for service in these years. These are credited service years, not exact deployment and return dates.

      Source
  16. 16 Sep 2015 – page cutoff*

    2d Battle Group / Battalion lineage

    Last documented: 2d Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage. The source establishes this last recorded status, not uninterrupted service through 2026. The striped bar extends to the page cutoff to keep the later research gap visible.

    Source

  17. 1 Jul 1957 – 1 Jul 1966

    4th Battle Group / Battalion lineage

    Inactive

    The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased.

    Source

  18. 1 Jul 1966 – 15 Feb 1969

    4th Battle Group / Battalion lineage

    11th Infantry Brigade · Separate

    This headquarters is not a division. Temporary attachments in the service entries below are distinct from the formal assignment.

    Source

    Deployments & overseas operations

    1. 1968-1971

      Vietnam

      4th Battle Group / Battalion lineage · Credited overseas service

      The Army lineage lists a unit decoration for service in these years. These are credited service years, not exact deployment and return dates. The labeled service overlaps an assignment change and is listed only once; consult the following assignment cards as well.

      Source
  19. 15 Feb 1969 – 30 Nov 1971

    4th Battle Group / Battalion lineage

    23d Infantry Division (Americal)

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  20. 30 Nov 1971 – 16 Oct 2006

    4th Battle Group / Battalion lineage

    Inactive

    The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased.

    Source

  21. 16 Oct 2006 – page cutoff*

    4th Battle Group / Battalion lineage

    Last documented: No assigned division

    The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit. The source establishes this last recorded status, not uninterrupted service through 2026. The striped bar extends to the page cutoff to keep the later research gap visible.

    Source

Sources and scope

Army Center of Military History lineage certificates provide the dated backbone. Regimental associations and secondary histories supplement individual operations and battalions. Where the evidence stops, the page says so. A page cutoff is not a claim that every unit directory was current on that date.

Earlier battalions are covered by common regimental service; separately dated lineages and substantiated later battalions receive their own rows or notes. A unit graphic alone is not evidence of a battalion assignment. Reserve, training and inactive organizations are distinguished from active combat units.

  1. U.S. Army Center of Military History: 3d Infantry Regiment
  2. U.S. Army Center of Military History: 1st Battalion 3d Infantry Regiment
  3. U.S. Army Center of Military History: 2d Battalion 3d Infantry Regiment
  4. U.S. Army Center of Military History: 4th Battalion 3d Infantry Regiment
  5. 3d Infantry Regiment history (Wikipedia; secondary)

Patch artwork

Unmodified artwork from Wikimedia Commons; individual file pages identify the artist and license. Insignia represent the divisions, not regimental affiliation badges.