33d Infantry Regiment
Not yet constituted / organized
This timeline begins in 1916. The cited organization had not yet been constituted or organized during this interval; its formation follows.
First division shownPanama Canal Division3 Jul 1921
Separate unit histories2 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. Battalion rows follow headquarters lineages, often descended from lettered companies, rather than assuming that the old regimental battalions continued unchanged.
The Panama Canal Division became inactive in 1932; the regiment remained assigned on paper until 1938 while attached to the Pacific Sector. June 1919 is the earliest separate-regiment status established here, not a claimed assignment date. Canal and Caribbean defense service did not produce a combat campaign honor.
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 – 1 Jul 1916
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1 Jul 1916 – 1 Jun 1919
33d Infantry Regiment
Assignment not established
The available record does not establish a precise assignment throughout this interval. No division is inferred.
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1 Jun 1919 – 3 Jul 1921
33d 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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3 Jul 1921 – 10 Oct 1938
33d Infantry Regiment
Panama Canal Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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10 Oct 1938 – 26 Jun 1944
33d 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.
Deployments & overseas operations
1941-1944
Caribbean defense
33d Infantry Regiment · Deployment / overseas operation
Battalions served in Trinidad and its associated defense area; detachments also served in Surinam and Aruba. The labeled service overlaps an assignment change and is listed only once; consult the following assignment cards as well.
Source
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26 Jun 1944 – 1 Feb 1946
33d 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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1 Feb 1946 – 1 Sep 1948
33d 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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1 Sep 1948 – 4 Jan 1950
33d 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 Jan 1950 – 2 Dec 1954
33d 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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2 Dec 1954 – 26 May 1956
33d Infantry Regiment
23d Infantry Division (Americal)
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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26 May 1956 – page cutoff*
33d Infantry Regiment
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
1st Battle Group / Battalion lineage · Caribbean defense
The battalion moved to Trinidad in 1941; detachments guarded bauxite production in Surinam. It moved from Surinam to Aruba in June 1943.
Service note · dates incomplete
3d Battle Group / Battalion lineage · Korean War personnel transfer
The 3d Battalion furnished personnel to the 65th Infantry during the Korean War. That transfer is not treated as a deployment of the entire 33d Infantry Regiment.
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.
Patch artwork
Unmodified artwork from Wikimedia Commons; individual file pages identify the artist and license. Insignia represent the divisions, not regimental affiliation badges.
- 23d Infantry Division (Americal) · file and credit · public domain
