Infantry timelines · Infantry numbers 1–200

171st Infantry Regiment

A century of division assignments

1916–2026 · Regimental service, battle groups, battalions and deployments.

171st Infantry Regiment unit graphic
171st Infantry Regiment
First division shown43d Infantry Division22 Nov 1921
Separate unit histories0 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.

Maine’s 171st Infantry was redesignated the 103d Infantry on 31 December 1921. Its subsequent wars and division assignments belong on the 103d page.

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.

The dated record

Division timeline

Battalion overview →

No deployment with sufficiently established dates is plotted for this regiment. Read the assignment cards and service notes for its garrison, training and successor-unit history.

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. 1 Jan 1916 – 22 Nov 1921

    171st Infantry Regiment

    Assignment not established

    The available record does not establish a precise assignment throughout this interval. No division is inferred.

    Source

  2. 22 Nov 1921 – 31 Dec 1921

    171st Infantry Regiment

    43d Infantry Division

    Division names are normalized across historical redesignations. This entry follows the cited unit lineage.

    Source

  3. 31 Dec 1921 – page cutoff*

    171st Infantry Regiment

    Last documented: Redesignated as 103d Infantry

    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.

    Source

Sources and scope

Army Center of Military History lineage certificates, regimental associations and secondary histories document assignments, operations and battalions. Exact lineage dates and approximate historical coverage are distinguished. 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.

  1. 103d 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.