Were any US elections postponed or altered due to World War II events?

1. Wartime ballots kept their calendar — elections were held as scheduled

Primary source summaries and contemporary overviews show that presidential elections were conducted on Tuesday, November 5, 1940 and Tuesday, November 7, 1944, and that midterm elections were held on November 3, 1942 — all on the normal federal election days — with no evidence in these sources that any of those national contests were postponed because of World War II ^{[6] [1] [3]}. The 1944 contests occurred “during the final stages of World War II,” yet Franklin D. Roosevelt was re-elected on the scheduled November date and Congress’s regular elections were similarly held on schedule ^{[2] [1]}.

2. The war altered politics and turnout but not the election timetable

Although the wartime context decisively influenced voter behavior and party fortunes, those effects were political rather than procedural: Roosevelt’s wartime leadership was a major factor in his 1940 and 1944 victories, helping him breach the two‑term tradition and secure a fourth term in 1944 ^{[6] [5]}. The 1942 midterms likewise reflected wartime dynamics, producing gains for Republicans even as Democrats retained control, but sources treat those as normal electoral outcomes rather than the product of altered scheduling ^{[3] [4]}.

3. Concrete wartime consequences recorded in sources — turnout and electoral shifts

The sources document significant wartime consequences that affected how Americans voted, including unusually low voter turnout in 1942 — a notably low 33.9% in one account — and shifts in party strength that produced Republican pickups in both houses in that cycle ^[3]. By 1946, the first postwar national elections registered a sharper reaction against the incumbent party, underscoring that wartime and immediate postwar conditions shaped electoral results and party fortunes even while formal election dates remained unchanged ^[4].

4. High‑profile wartime events intersected with elections, but did not stop them

Reporting emphasizes that major wartime developments coincided with electoral politics — for example, D‑Day occurred in June 1944 during the presidential campaign that culminated in November 1944 — yet the campaign and voting timetable stayed intact and the wartime context was instead a dominant campaign theme that favored incumbency in some cycles ^{[7] [1]}. The abrupt post‑election death of Roosevelt in April 1945 is a wartime‑era fact noted in these sources, but it was a succession event after the scheduled 1944 election rather than a cause to postpone it ^{[2] [1]}.

5. Limits of the available reporting and alternative perspectives

The reviewed sources uniformly present wartime elections as held on schedule and emphasize political effects rather than calendar changes ^{[2] [1] [3]}. They do not, however, provide exhaustive treatment of every local administrative accommodation (such as absentee voting procedures for servicemembers) or state‑level emergency plans that might have adjusted election mechanics without changing dates; those specific procedural adaptations are not detailed in the provided material and so cannot be affirmed or denied here from these sources alone ^{[4] [7]}. Historians and institutions like the National WWII Museum and academic studies argue that wartime conditions strengthened incumbents like FDR in 1940 and 1944, a perspective consistent across sources ^{[8] [5]}.

Conclusion — direct answer to the question

Based on the reporting reviewed, no U.S. federal elections were postponed or had their dates altered because of World War II; elections in 1940, 1942, and 1944 took place on their normal schedules, and the war’s impact manifested through voter behavior and electoral outcomes rather than through calendar changes ^{[6] [3] [1]}.