51st 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 shown6th Infantry Division16 Nov 1917
Separate unit 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 10 Sep 1943; 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.
The Company F row includes its Company C, 10th Armored Infantry Battalion and constabulary predecessors. A temporary attachment is not a formal division assignment. The secondary regimental history and reproduced company certificate disagree on the 1939-1940 relief date; the regimental row follows the former.
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 – 15 May 1917
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15 May 1917 – 16 Nov 1917
51st 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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16 Nov 1917 – 22 Sep 1921
51st Infantry Regiment
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1918
France
51st Infantry Regiment · Campaign service
Campaign participation is recorded in the cited history. The year label summarizes campaign service, not an exact overseas tour.
Source
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22 Sep 1921 – 15 Aug 1927
51st Infantry Regiment
Inactive · 6th Infantry Division
The unit was inactive but retained the division assignment shown. Paper assignments and Reserve-officer training are not active combat service.
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15 Aug 1927 – 1 Oct 1933
51st Infantry Regiment
Inactive · 9th Infantry Division
The unit was inactive but retained the division assignment shown. Paper assignments and Reserve-officer training are not active combat service.
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1 Oct 1933 – 16 Oct 1939
51st Infantry Regiment
Inactive · 6th Infantry Division
The unit was inactive but retained the division assignment shown. Paper assignments and Reserve-officer training are not active combat service.
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16 Oct 1939 – 15 Apr 1941
51st 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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15 Apr 1941 – 10 Sep 1943
51st Infantry Regiment
4th Armored Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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10 Sep 1943 – 1 May 1946
Company F · Headquarters lineage
4th Armored Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
1944-1945
Western Europe
Company F · Headquarters lineage · Deployment / campaign service
Company F's predecessor served as Company C, 10th Armored Infantry Battalion, in the 4th Armored Division.
Source
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1 May 1946 – 20 Dec 1948
Company F · Headquarters lineage
14th Constabulary Regiment
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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20 Dec 1948 – 15 Jun 1954
Company F · Headquarters lineage
Inactive · 4th Armored Division
The unit was inactive but retained the division assignment shown. Paper assignments and Reserve-officer training are not active combat service.
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15 Jun 1954 – 1 Apr 1957
Company F · Headquarters lineage
4th Armored Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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1 Apr 1957 – 25 Sep 1967
Company F · Headquarters 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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25 Sep 1967 – 26 Dec 1968
Company F · Headquarters lineage
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
1967-1968
Vietnam
Company F · Headquarters lineage · Deployment / overseas operation
Long-range patrol service; the official lineage inactivation date is 26 December 1968. 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 Dec 1968 – 16 Dec 1986
Company F · Headquarters 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 1986 – 15 Nov 1991
Company F · Headquarters lineage
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
1990-1991
Southwest Asia
Company F · Headquarters 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
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15 Nov 1991 – 16 Apr 1995
Company F · Headquarters 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 1995 – 15 Mar 2009
Company F · Headquarters lineage
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
2007-2008
Iraq
Company F · Headquarters 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
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15 Mar 2009 – 16 Jan 2011
Company F · Headquarters 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 Jan 2011 – 15 Nov 2013
Company F · Headquarters lineage
1st Armored Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
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15 Nov 2013 – 16 Nov 2014
Company F · Headquarters 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 Nov 2014 – page cutoff*
Company F · Headquarters 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.
Service note · dates incomplete
1st Battle Group / Battalion lineage · Mechanized battalion
The 1st Battalion served with the 2d Armored Division after 1957, the 4th Armored Division after 1963, and the 1st Armored Division from 10 May 1971. It inactivated on 16 June 1984.
Service note · dates incomplete
Company E · Headquarters lineage · Long-range surveillance
Company E served in Germany as V Corps' surveillance company from 1986. Its overseas service included Bosnia, Kosovo and Iraq; tour boundaries are not established here.
Service note · dates incomplete
51st Armored Infantry Battalion · Predecessor · Armored and constabulary predecessor
The 51st Armored Infantry Battalion became the 51st Constabulary Squadron in May 1946.
Service note · dates incomplete
53d Armored Infantry Battalion · Predecessor · Armored and constabulary predecessor
The regiment's former 1st Battalion became the 53d Armored Infantry Battalion in 1943, then a constabulary squadron in May 1946.
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.
- Company F, 51st Infantry: reproduced Army lineage, 15 June 2011
- 51st 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.
- 6th Infantry Division · file and credit · public domain
- 9th Infantry Division · file and credit · public domain
- 4th Armored Division · file and credit · public domain
- 1st Armored Division · file and credit · CC BY-SA 4.0 (Noclador; unmodified)
