Smith took the oath as U.S. Senator from Maine, becoming the first woman ever to serve in both the House and Senate.
On January 3, 1949, Margaret Chase Smith was sworn in as a United States Senator representing Maine, having won election to the seat in her own right in November 1948. This moment made her the first woman in American history to serve in both the U.S. House of Representatives and the U.S. Senate, a distinction that remained unmatched for years afterward.
Smith's path to the Senate was notable because, unlike many of the small number of women who had previously entered Congress via widow's succession or appointment, she won this seat through a direct, hard-fought statewide election victory, defeating three male opponents in the Republican primary and then the general election. This established her legitimacy as a senator in her own right rather than as a placeholder or symbolic successor.
Her Senate tenure, which would ultimately span 24 years (1949-1973), made her one of the longest-serving women in the history of Congress up to that time. During her service she sat on powerful committees including Armed Services, and she became known for her independence, integrity, and willingness to break with her own party when she believed principle demanded it—most famously demonstrated a year later in her Declaration of Conscience speech. Her swearing-in is regarded as a landmark moment in the long struggle for women's full political representation in the United States.