Infantry timelines · Infantry numbers 1–200
A century of division assignments
1916–2026 · Regimental service, battle groups, battalions and deployments.
No U.S. Regular Army infantry regiment was constituted under this number. The numbering row and any separately numbered battalion histories have different identities.
Regular Army infantry regimental numbers 92–100 were allotted but never constituted. This is a numbering record, not a regiment with invented divisions or battalions. Separately numbered battalions, where documented, are identified below and do not establish a regiment of the same number. The 100th Battalion served with the 442d Infantry. Operational attachments in Italy and France must be distinguished from a permanent divisional assignment.
Division names appear in the timeline. No verified patch artwork is included for these assignments.
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
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.
Explore a date
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
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.
100th Infantry · Regimental numbering record
This regimental number was never constituted in the numbering history cited below. Related separate battalions are distinct organizations, not battalions of a regiment with this number. 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.
100th Infantry Battalion / 100th Battalion, 442d Infantry
This timeline begins in 1916. The cited organization had not yet been constituted or organized during this interval; its formation follows.
100th Infantry Battalion / 100th Battalion, 442d Infantry
The cited record establishes service outside an assigned division. Higher headquarters and temporary operational attachments could still direct the unit.
1943-1944
100th Infantry Battalion / 100th Battalion, 442d Infantry · Deployment / campaign service
Operational attachment of the separate battalion, later incorporated into the 442d Infantry; not an assignment of a 100th Infantry Regiment.
Source1944
100th Infantry Battalion / 100th Battalion, 442d Infantry · Deployment / campaign service
The battalion fought with the 442d during its attachment to the 36th Division in the Vosges.
Source100th Infantry Battalion / 100th Battalion, 442d Infantry
The unit or its headquarters lineage was inactive. This status does not imply that every inherited honor or divisional affiliation was erased.
100th Infantry Battalion / 100th Battalion, 442d Infantry
Army Reserve service. Battalion, battle-group and regimental redesignations are recorded here without inferring a maneuver-division assignment.
100th Infantry Battalion / 100th Battalion, 442d Infantry
Army Reserve service. Battalion, battle-group and regimental redesignations are recorded here without inferring a maneuver-division assignment.
100th Infantry Battalion / 100th Battalion, 442d Infantry
Army Reserve service. Battalion, battle-group and regimental redesignations are recorded here without inferring 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.
2005-2006
100th Infantry Battalion / 100th Battalion, 442d Infantry · Deployment / campaign service
Credited service years in the Army lineage certificate; not exact departure and return dates.
Source2008-2009
100th Infantry Battalion / 100th Battalion, 442d Infantry · Deployment / campaign service
Credited service years in the Army lineage certificate.
SourceArmy 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.
Unmodified artwork from Wikimedia Commons; individual file pages identify the artist and license. Insignia represent the divisions, not regimental affiliation badges.