20th Infantry Regiment
Assignment not established
The available record does not establish a precise assignment throughout this interval. No division is inferred.
First division shown10th Division9 Jul 1918
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 15 Nov 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.
-
1 Jan 1916 – 9 Jul 1918
-
9 Jul 1918 – 14 Feb 1919
20th Infantry Regiment
10th Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
-
14 Feb 1919 – 18 Sep 1920
20th 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.
-
18 Sep 1920 – 16 Oct 1939
20th Infantry Regiment
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
-
16 Oct 1939 – 10 Jan 1949
20th 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
20th Infantry Regiment · Campaign service
Campaign participation is recorded in the Army lineage. The year label summarizes campaign service, not an exact overseas tour.
Source
-
10 Jan 1949 – 4 Oct 1950
20th 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.
-
4 Oct 1950 – 3 Apr 1956
20th Infantry Regiment
6th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
-
3 Apr 1956 – 15 Nov 1957
20th 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.
-
15 Nov 1957 – 24 Jun 1960
5th 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.
-
24 Jun 1960 – 1 Jan 1966
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.
-
1 Jan 1966 – 25 Sep 1967
5th 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.
-
25 Sep 1967 – 1 Feb 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.
-
1 Feb 1969 – 30 Jun 1971
5th 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.
-
30 Jun 1971 – 16 Aug 1972
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.
-
16 Aug 1972 – 16 Aug 1986
5th 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.
-
16 Aug 1986 – 16 Aug 1995
5th Battle Group / Battalion lineage
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
-
16 Aug 1995 – 16 Sep 2000
5th Battle Group / Battalion lineage
25th Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
-
16 Sep 2000 – 27 Jul 2005
5th Battle Group / Battalion lineage
2d Infantry Division
Division names are normalized across historical redesignations. This entry follows the cited unit lineage.
Deployments & overseas operations
2003-2004
Iraq
5th 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
-
27 Jul 2005 – page cutoff*
5th 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
2006-2007
Iraq
5th 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.
Source2009-2010
Iraq
5th 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
Service note · dates incomplete
1st Battalion · Vietnam
Served with the 11th Infantry Brigade in Vietnam, later part of the Americal Division. Complete day-level assignment boundaries are not established here.
Service note · dates incomplete
4th Battalion · Panama
Served with the 193d Infantry Brigade in Panama. The separate brigade was not an infantry division.
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: 20th Infantry Regiment
- U.S. Army Center of Military History: 5th Battalion 20th Infantry Regiment
- 20th 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
- 25th Infantry Division · file and credit · public domain
