The U.S. Congress currently has more women than ever before — with 23 female senators and 84 female representatives, women make up 20% of Washington lawmakers. But there remains a long way to go until the sexes are equally represented in Congress.

In fact, 20 states have never been represented by women in the U.S. Senate. (That doesn’t include states that have appointed but never elected a woman, like Georgia, which appointed the first woman to the Senate in 1922.) Five states have never elected a woman to the House. Vermont is the only state that has never sent a woman to either chamber of Congress.

“Everybody brings their life experience to the table, and we’ve found that women are more likely to prioritize issues affecting women, families and children,” says Debbie Walsh, director of the Center for American Women and Politics at Rutgers University. “It’s not that men don’t support many of those positions, but it takes women to raise those issues and put them on the agenda,” explains Walsh.

Click the play button below to watch as women gain seats in Congress over time. The first map shows all of Congress, or you can select a particular chamber. You can also drag the red dot to show a single point in time.

The first woman elected to serve in Congress was Jeannette Rankin of Montana, who won a House seat in 1916, four years before women were able to vote nationwide.

In the following years, many women were elected or appointed to fill their late husbands’ seats, as the Pew Research Center explains. But women without preexisting congressional ties gradually won more seats. By 1992, 24 female representatives and four female senators were elected in one go, in what came to be known as “The Year of the Woman.”

There are now a record number of women running in the 2018 midterm elections, according to the Center for American Women in Politics. And with women running in at least three states that have never before had female senators, there’s a chance history could be made come November.

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