(CNN) Once Cindy Hyde-Smith of Mississippi is sworn in as a US senator, there will be only one state remaining that has never sent a woman to either chamber in Congress -- Vermont.

Mississippi Gov. Phil Bryant formally announced Wednesday that Hyde-Smith, the state's agriculture commissioner, will fill the spot to be vacated by Sen. Thad Cochran, when he steps down April 1. Hyde-Smith also announced Wednesday her plans to run in the special election this November to permanently fill the seat.

Upon taking office, Hyde-Smith will become the 23rd woman currently in the Senate -- a record -- and sixth female Republican senator in office.

The Commonwealth of the Northern Mariana Islands also hasn't been represented by a woman either.

Fifty-one women have served in the Senate (34 Democrats, 17 Republicans). Hyde-Smith will become the 52nd.