9th Infantry Regiment
Assignment not established
The available record does not establish a precise assignment throughout this interval. No division is inferred.
First division shown2d Infantry Division22 Sep 1917
Separate battalion histories5 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 20 Jun 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
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 – 22 Sep 1917
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22 Sep 1917 – 20 Jun 1957
9th Infantry Regiment
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1918
France: Aisne, Aisne-Marne, St. Mihiel and Meuse-Argonne
9th Infantry Regiment · Campaign service
Campaign participation is recorded in the Army lineage. The year label summarizes campaign service, not an exact overseas tour.
Source1944-1945
Normandy, Northern France, Rhineland, Ardennes-Alsace and Central Europe
9th Infantry Regiment · Campaign service
Campaign participation is recorded in the Army lineage. The year label summarizes campaign service, not an exact overseas tour.
Source1950-1953
Korea
9th 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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20 Jun 1957 – 16 Dec 1957
1st 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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16 Dec 1957 – 25 Jan 1963
1st 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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25 Jan 1963 – 16 Mar 1987
1st 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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16 Mar 1987 – 16 Apr 1987
1st 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 Apr 1987 – 16 Aug 1995
1st Battle Group / Battalion lineage
7th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1989-1990
Panama
1st Battle Group / Battalion lineage · Deployment / overseas operation
Participated in Operation Just Cause with the 7th Infantry Division.
Source
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16 Aug 1995 – page cutoff*
1st 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.
Deployments & overseas operations
2004-2005
Iraq
1st Battle Group / Battalion lineage · Deployment / overseas operation
Deployed from Korea to Iraq; subsequent stateside service continued the battalion lineage.
Source
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20 Jun 1957 – 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 – 21 Jun 1971
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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21 Jun 1971 – 15 Aug 1975
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 Aug 1975 – 15 Dec 1979
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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15 Dec 1979 – 29 Apr 1983
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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29 Apr 1983 – 16 Aug 1995
2d Battle Group / Battalion lineage
7th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1989-1990
Panama
2d Battle Group / Battalion lineage · Deployment / overseas operation
Participated in Operation Just Cause with the 7th Infantry Division.
Source
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16 Aug 1995 – 16 Jun 2005
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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16 Jun 2005 – 1 Jun 2015
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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1 Jun 2015 – 1 Jul 2015
2d Battle Group / Battalion lineage
Assignment not established
The available record does not establish a precise assignment throughout this interval. No division is inferred.
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1 Jul 2015 – page cutoff*
2d 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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1 Jun 2006 – 17 Mar 2014
4th Battle Group / Battalion lineage
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
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17 Mar 2014 – page cutoff*
4th Battle Group / Battalion lineage
Last documented: 4th 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.
Service note · dates incomplete
3d Battalion · Panama
Participated in Operation Just Cause in 1989-1990 with the 7th Infantry Division. Exact assignment boundaries remain incomplete.
Service note · dates incomplete
4th Battalion · Earlier service: Alaska, Vietnam and Southwest Asia
Before the dated Fort Carson row, the battalion served in Alaska, fought with the 25th Infantry Division in Vietnam, and deployed to Iraq and Afghanistan. The secondary history also identifies element deployments to Afghanistan in 2018-2019 and Iraq/Syria in 2021-2022.
Service note · dates incomplete
5th Battalion · Alaska
The regimental history records activation with the 6th Infantry Division in 1986 and reflagging in 1994. Exact day-level boundaries remain unverified.
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: 9th Infantry Regiment
- U.S. Army Center of Military History: 1st Battalion 9th Infantry Regiment
- U.S. Army Center of Military History: 2d Battalion 9th Infantry Regiment
- 1st Battalion, 22nd Infantry veterans: March 2014 reflagging
- 9th 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
- 7th Infantry Division · file and credit · public domain
- 4th Infantry Division · file and credit · public domain
