Democratic members of the U.S. House of Representatives are sworn in by Speaker Nancy Pelosi during the first session of the 117th Congress on Jan. 3, 2021. (Erin Scott/POOL/AFP via Getty Images)
Democratic members of the U.S. House of Representatives are sworn in by Speaker Nancy Pelosi during the first session of the 117th Congress on Jan. 3, 2021. (Erin Scott/POOL/AFP via Getty Images)

Women make up just over a quarter of all members of the 117th Congress – the highest percentage in U.S. history and a considerable increase from where things stood even a decade ago.

Women make up more than a quarter of the 117th U.S. Congress’ membership

Counting both the House of Representatives and the Senate, 144 of 539 seats – or 27% – are held by women. That represents a 50% increase from the 96 women who were serving in the 112th Congress a decade ago, though it remains far below the female share of the overall U.S. population. A record 120 women are serving in the newly elected House, accounting for 27% of the total. In the Senate, women hold 24 of 100 seats, one fewer than the record number of seats they held in the last Congress.

This analysis counts voting as well as nonvoting members of Congress. Figures for the 117th Congress exclude two House seats that were vacant as of early January. It also excludes Sens. Kamala Harris, who is expected to resign her seat ahead of her inauguration as vice president on Jan. 20, and Kelly Loeffler, who lost a runoff election in Georgia earlier this month. Both are set to be replaced by men.

This analysis builds on earlier Pew Research Center work to analyze the gender makeup of Congress.

In the House, one New York race has not been called yet, and one Louisiana seat is empty because the congressman-elect died before he could be sworn in. Both seats were vacant when Congress was sworn in on Jan. 3, 2021, so the current number of representatives is 439. This analysis includes nonvoting members.

Independent members of Congress are counted with the party they caucus with.

Because Sen. Kamala Harris will ascend to the vice presidency this month, we are not including her in the count of female senators. We are, however, counting her seat as Democrat-held because a Democrat has been named to take her place.

For historical data on Congress, we used data from the Biographical Directory of the United States Congress, the U.S. House of Representatives Office of the Historian, the Congressional Research Service’s “Women in the United States Congress, 1917-2014” and CQ Roll Call. For 2020-21 election results, we used data from Ballotpedia and the Associated Press, as well as news reports.

Women make up a much bigger share of congressional Democrats (38%) than Republicans (14%). Across both chambers, there are 106 Democratic women and 38 Republican women in the new Congress. Women account for 40% of House Democrats and 32% of Senate Democrats, compared with 14% of House Republicans and 16% of Senate Republicans.

The 2020 general election sent just one new congresswoman to the Senate, Republican Cynthia Lummis of Wyoming, making her the first female senator to represent that state.

Republican women made significant gains in the House in the most recent election cycle. Of the 27 newly elected representatives who are women, two-thirds (18) are Republicans. Between the 115th and 116th Congresses, the number of GOP women in the House fell from 25 to 15. That number doubled this year to 30, the highest total ever.

California Rep. Nancy Pelosi, a Democrat and the first female speaker of the House, is serving her fourth term as speaker after being reelected earlier this month. 

The partisan gender division hasn’t always looked this way. Until the 1929 stock market crash, most of the dozen women elected to the House were Republicans, and for several decades afterward the two parties were generally close in numbers in that chamber. But the gap widened in the 1970s and has persisted, despite a temporary narrowing during the Reagan-Bush 1980s. Of the 232 women elected to the House in 1992 or later, 157 (68%) have been Democrats, as have 27 of the 42 women (64%) who have served in the Senate since 1992.

The history of women in Congress

Milestones for women in Congress

Women have been in Congress for more than a century. The first, Republican Jeannette Rankin of Montana, was elected to the House in 1916, two years after her state gave women the vote. But it’s only been in the past few decades that women have served in more substantial numbers. About two-thirds of the women ever elected to the House (232 of 352, including the newest members of the 117th Congress) have been elected in 1992 or later.

The pattern is similar in the Senate: 42 of the 58 women who have ever served in the Senate – including Lummis, the newest female senator – took office in 1992 or later.

The 19th Amendment, which extended the franchise to women across the nation, was ratified in 1920. That November, Alice Mary Robertson of Oklahoma became the first woman to defeat an incumbent congressman. (She lost the seat back to him two years later.) In 1922, veteran suffragist Rebecca Latimer Felton of Georgia was appointed to fill a vacant Senate seat; when Congress was unexpectedly called back into session, Felton was sworn in as the first-ever female senator, though she only served for a day.

While women remained scarce in the Senate well into the 1980s, their numbers gradually, though not consistently, increased in the House – generally paralleling the expansion of women’s roles in society more broadly. In 1928, seven women were elected to the 71st Congress, a record at the time, and two more joined them later via special election. But that trend plateaued during the Great Depression and World War II. It wasn’t until after the war that the upward trajectory of women in Congress resumed, with 18 women serving in the House in 1961-62.

Although the 1970s saw prominent figures such as Barbara Jordan, Elizabeth Holtzman and Bella Abzug enter Congress, women’s overall numbers didn’t change much until 1981, when their House caucus exceeded 20 members for the first time. The big jump, however, came in 1992 – later dubbed “The Year of the Woman” – when four new female senators and 24 new congresswomen were elected. Academics have offered various explanations for why 1992 was such a breakthrough year for women in Congress, including an unusually large number of open seats due to redistricting and backlash from the Clarence Thomas-Anita Hill hearings.

‘Widow’s succession’ in Congress

Well into the 1970s, one of the most common ways for a woman to enter Congress was by succeeding her deceased husband or father, either by election or appointment. Of the 90 women who served in the House between 1916 and 1980, 31 were initially elected to their husband’s seat after he died; three were chosen to replace their husbands on the ballot when the men died before Election Day; and one, Winnifred Mason Huck of Illinois, was elected in 1922 to fill the last four months of her late father’s term. (Another early congresswoman, Katherine Gudger Langley of Kentucky, won her husband’s seat in 1926 after he resigned following his conviction for violating Prohibition laws.)

‘Widow’s succession’ less common than it used to be

Like Langley, most of the holders of these so-called “widow’s succession” seats stayed in Congress for only a term or two. But some went on to distinguished careers on Capitol Hill. Margaret Chase Smith of Maine, for instance, won a special election in 1940 to fill the last seven months of her husband’s term. Smith went on to win four full House terms on her own, then was elected to four terms in the Senate, thereby becoming the first woman to serve in both chambers. Lindy Boggs, who was elected to her husband’s seat in 1973 after he was presumed killed in a plane crash, served nearly 18 years. She later was named U.S. ambassador to the Holy See.

Six of the 14 women who served in the Senate before 1980 were either elected or appointed to fill their late husbands’ seats. Of those, only two (Hattie Caraway of Arkansas and Maurine Brown Neuberger of Oregon) subsequently won full terms in their own right.

Note: This is an update of a post originally published Dec. 18, 2018.

Carrie Blazina  is a digital producer at Pew Research Center.
Drew DeSilver  is a senior writer at Pew Research Center.