Was there ever an election in the US that was overturned by the courts due to fraud?

Question

Was there ever an election in the US (state or federal-level) whose result was overturned by the courts due to vote fraud?

If so, what was the most recent such instance?

Answer 1

Sort of, by which I mean invalidated (i.e. there was a rerun), not overturned (i.e. the other side was not just declared victor). And the election itself was invalidated by the canvassing board (basically by not certifying it), not by the courts, although the latter were involved in prosecuting the actual illegalities that occurred. I'm talking about the 2018 North Carolina's 9th congressional district election.

The NYT also mentions (in a 2020 article):

There was the case in Paterson, N.J., earlier this year, for instance, in which a judge recommended a do-over election for a seat on the City Council after evidence surfaced that mail-in ballots had been tampered with. (Just 240 votes separated the first- and second-place candidates.)

Goes over some highly contested but not invalidated elections from more than a century ago, to continue:

There have been more recent cases in which fraud rendered an election invalid. In one high-profile example, a Florida judge voided Miami’s mayoral election in 1998 and ordered a new vote, citing “a pattern of fraudulent, intentional and criminal conduct” in the casting of absentee ballots.

I haven't read much more detail(s) on these, but a quick search found a more detailed article on the N.J. election; in that case it seems it was a judge who actually invalidated (but not overturned) the election. In parallel with that, there are ongoing criminal prosecutions.

There are also news articles on the 1997 Miami election that was invalided in the spring of the following year. (Although CNN uses the word "overturned" there, the details of the article show that the judge ordered a new election to be held. There were also some criminal prosecutions launched in that case.)

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For US elections that more significantly depart the modern standards, you could read my summary of the 1876 affair in Florida to another question. The Florida Supreme Court there ordered the state canvassing board to recount in a different way, which produced a different winner as the governor of Florida, i.e. you can say that election was effectively overturned by a court (since there was no rerun), albeit somewhat indirectly. (The affair is much more complicated as the new governor also tried to change the presidential electors [via a new canvassing board], but that attempt was ultimately rejected by the US Congress.)

Answer 2

Wikipedia writes the following about Kansas before it became a US state (Kansas joined the Union on January 29, 1861):

In November 1854, thousands of armed pro-slavery men known as "Border Ruffians" or "Southern Yankees", mostly from Missouri, poured into the Kansas Territory and swayed the vote in the election for a non-voting delegate to Congress in favor of pro-slavery Democratic candidate John Wilkins Whitfield. The following year, a congressional committee investigating the election reported that 1,729 fraudulent votes were cast compared to 1,114 legal votes. In one location, only 20 of the 604 voters were residents of the Kansas Territory; in another, 35 were residents and 226 non-residents.

There are in fact multiple old elections which saw fraud, however, none were overturned due to various compromises.

Answer 3

In 1994 a Pennsylvania senate race was overturned by a Federal court.

https://www.nytimes.com/1994/02/19/us/vote-fraud-ruling-shifts-pennsylvania-senate.html

An appeals court later changed this decision and simply voided the results.