It's so common that political scientists call it "widow's succession."
Democrats
Mary Jo Kopechne Mahoney: One of many congressional widows who succeeded a deceased spouse through appointment or special election.
Lurleen Wallace: Ran for Alabama governor in 1966 largely as a stand-in for her husband when he was term-limited.
Blanche Lincoln and many others came from established political families where name recognition played a major role.
Republicans
Darline Graham Nordone: Appointed in 2026 to temporarily fill Lindsey Graham's Senate seat after his death.
Lisa Murkowski: Appointed to the U.S. Senate in 2002 by her father, Alaska Governor Frank Murkowski, after he vacated the seat.
Cindy McCain: Appointed in 2021 to fill a vacant Arizona Senate seat that had previously been held by her late husband.