1st Infantry Regiment
Assignment not established
The available record does not establish a precise assignment throughout this interval. No division is inferred.
First division shown13th Division (World War I)11 Sep 1918
Separate battalion histories6 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 15 May 1958; 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
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.
At a glance
Assignments across time
Bar widths follow elapsed time.
Scroll horizontally on a small screen. Select a segment to open its dated entry. Diamond markers open deployments; their positions indicate the labeled year, not an exact start date or duration. Short assignments are easier to inspect in the list below.
- Division assignment
- 1st Infantry
- 2d Infantry
- 8th Infantry
- Separate headquarters
- Training / academy
- Inactive
- Unverified / last documented
Explore a date
Who were they with?
Look up the dated rows below. Service notes with incomplete dates are excluded; last-documented results do not certify a current assignment.
The dated record
Division timeline
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.
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1 Jan 1916 – 11 Sep 1918
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11 Sep 1918 – 8 Mar 1919
1st Infantry Regiment
13th Division (World War I)
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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8 Mar 1919 – 27 Jul 1921
1st 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.
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27 Jul 1921 – 16 Oct 1939
1st Infantry Regiment
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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16 Oct 1939 – 10 Jan 1949
1st Infantry Regiment
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1944-1945
New Guinea and Luzon
1st Infantry Regiment · Campaign service
Campaign participation is recorded in the Army lineage. The year label summarizes campaign service, not an exact overseas tour.
Source
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10 Jan 1949 – 4 Oct 1950
1st 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.
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4 Oct 1950 – 3 Apr 1956
1st Infantry Regiment
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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3 Apr 1956 – 15 May 1956
1st 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.
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15 May 1956 – 15 May 1958
1st Infantry Regiment
United States Military Academy
Institutional or training service. This is a command relationship, not a maneuver-division assignment.
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15 May 1958 – page cutoff*
1st Battle Group / Battalion lineage
Last documented: United States Military Academy
Institutional or training service. This is a command relationship, not a maneuver-division assignment. 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.
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15 May 1958 – 14 Jun 1958
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.
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14 Jun 1958 – 10 May 1963
2d Battle Group / Battalion lineage
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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10 May 1963 – 15 Sep 1965
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.
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15 Sep 1965 – 15 Feb 1969
2d Battle Group / Battalion lineage
196th Infantry Brigade · Separate
This headquarters is not a division. Temporary attachments in the service entries below are distinct from the formal assignment.
Deployments & overseas operations
1966
South Vietnam
2d Battle Group / Battalion lineage · Deployment / overseas operation
Deployed with the 196th Light Infantry Brigade.
Source
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15 Feb 1969 – 1 Nov 1971
2d Battle Group / Battalion lineage
23d Infantry Division (Americal)
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1969-1971
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. More than one assignment falls in the opening year; this year-level service marker does not establish the assignment on a particular deployment day. The labeled service overlaps an assignment change and is listed only once; consult the following assignment cards as well.
Source
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1 Nov 1971 – 21 Jul 1972
2d Battle Group / Battalion lineage
196th Infantry Brigade · Separate
This headquarters is not a division. Temporary attachments in the service entries below are distinct from the formal assignment.
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21 Jul 1972 – 16 Feb 1991
2d Battle Group / Battalion lineage
9th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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16 Feb 1991 – 14 Jan 1994
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.
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14 Jan 1994 – 16 Dec 1995
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.
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16 Dec 1995 – 16 Apr 1998
2d Battle Group / Battalion lineage
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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16 Apr 1998 – 16 Dec 2006
2d Battle Group / Battalion lineage
172d Infantry Brigade · Separate
This headquarters is not a division. Temporary attachments in the service entries below are distinct from the formal assignment.
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16 Dec 2006 – 17 Apr 2007
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.
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17 Apr 2007 – 22 Jul 2010
2d Battle Group / Battalion lineage
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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22 Jul 2010 – 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.
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24 Nov 1967 – 24 Jul 1968
4th Battle Group / Battalion lineage
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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24 Jul 1968 – 21 Jul 1969
4th Battle Group / Battalion lineage
No assigned division
The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit.
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21 Jul 1969 – page cutoff*
4th Battle Group / Battalion lineage
Last documented: Inactive
The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased. 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.
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24 Nov 1967 – 24 Jul 1968
5th Battle Group / Battalion lineage
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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24 Jul 1968 – 21 Jul 1969
5th Battle Group / Battalion lineage
No assigned division
The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit.
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21 Jul 1969 – page cutoff*
5th Battle Group / Battalion lineage
Last documented: Inactive
The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased. 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.
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24 Nov 1967 – 24 Jul 1968
6th Battle Group / Battalion lineage
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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24 Jul 1968 – 21 Jul 1969
6th Battle Group / Battalion lineage
No assigned division
The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit.
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21 Jul 1969 – page cutoff*
6th Battle Group / Battalion lineage
Last documented: Inactive
The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased. 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.
Service note · dates incomplete
3d Battalion · Vietnam service
Served with the 11th Infantry Brigade in Vietnam and subsequently the Americal Division. The secondary history dates its inactivation to 1971; exact assignment boundaries are not established here.
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.
- U.S. Army Center of Military History: 1st Infantry Regiment
- U.S. Army Center of Military History: 1st Battalion 1st Infantry Regiment
- U.S. Army Center of Military History: 2d Battalion 1st Infantry Regiment
- 1st 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.
- 2d Infantry Division · file and credit · public domain
- 6th Infantry Division · file and credit · public domain
- 23d Infantry Division (Americal) · file and credit · public domain
- 9th Infantry Division · file and credit · public domain
