When was the last time both major party candidates in a US presidential election had the same home state at the time of the election?
In 1920, both major-party candidates came from Ohio, and the third-party candidate came from next door in Indiana.
In addition, both major-party vice-presidential candidates later became President, it was the first election where women could vote, and the third-party candidate was running for office while in prison.
1944 - FDR and Thomas Dewey were both from New York.
Before that, 1920 - Harding and Cox were both from Ohio. and both were newspaper editors.
Also 1904 (Teddy Roosevelt & Alton Parker, both of NY) and 1860 (Abraham Lincoln & Stephen Douglas, both of Illinois).
Nitpickery, but more than a dozen states had women’s suffrage before 1920. That was the first presidential election after ratification of the 19th Amendment, which expanded the franchise nationwide.