The Mississippi governor’s appointment of Cindy Hyde-Smith to the Senate next month marks a milestone: She will be the state’s first woman in Congress.

And that would leave Vermont as the lone state in the union to have never sent a female lawmaker to Washington. 

Hyde-Smith, a Republican who is currently the state’s agriculture and commerce commissioner, will replace longtime GOP Sen. Thad Cochran, who is stepping down April 1 for health reasons.

It also means that the Senate — once Hyde-Smith is sworn in — would have 23 female members, an all-time high. That group includes Minnesota Democrat Tina Smith who was appointed earlier this year to fill the seat vacated by Sen. Al Franken.

Not counting Mississippi, 20 states have never sent a woman to the world’s greatest deliberative body — and no woman has ever been at the helm of either party in the Senate.

Women currently make up about 19 percent of the House (slightly lower than the Senate’s soon-to-be 23 percent). Five states have yet to send a woman to the House — Alaska, Iowa, Mississippi, North Dakota and Vermont.

Ryan Kelly contributed to this report.Watch: Pelosi Looks Toward Future As She Makes Smithsonian Donation