Correction: An earlier version of this story had an incorrect party affiliation for Katrina Shealy, who was elected to the South Carolina state Senate. She is a Republican.

Twenty years after the election that was heralded as the “year of the woman” comes another one that could be called that.

The next Congress will include the largest number of women ever among its membership — 20 in the Senate, an increase of two, and at least 77 in the House, up by four, with two others vying in races that had not been called late Wednesday.

In January, New Hampshire will become the first state to have women holding all its top elected positions: Maggie Hassan, the Democrat who was elected governor; its two current U.S. senators, Democrat Jeanne Shaheen and Republican Kelly Ayotte; and a two-woman House delegation, Democrats Carol Shea-Porter and Ann McLane Kuster, both of whom unseated Republican incumbents.

The increase in congressional diversity goes beyond gender, however, especially on the Democratic side.

In the House, white males will for the first time be in the minority in the Democratic caucus, according to a tally by the office of Minority Leader Nancy Pelosi (Calif.).

When the 113th Congress begins in January, the expected 200 Democrats of the House will include 61 women, 43 African Americans, 27 Hispanics and 10 Asian Americans. Five will be openly gay, and one bisexual.

Gender-related issues — arguments over abortion, the definition of rape and whether medical insurance should cover contraception — assumed a larger role than many expected this election year. But that is not the only reason, or possibly even a major one, for the greater numbers of women running for and winning elected office.

Debbie Walsh, who runs the Center for American Women and Politics at Rutgers University, noted that once-a-decade redistricting created opportunities for newcomers. Thirteen of the women elected to the House won open seats.

The biggest gain may be that women running for office is becoming less remarkable. Gender played little role in many of the races.

“It’s where you are on the issues, what your philosophy is, if you’re in touch with people of your state,” said Deb Fischer, a little-known Nebraska legislator who shocked the state’s political establishment by winning the Republican primary in May and who then handily beat former governor and senator Bob Kerrey on Tuesday.

Fischer was the first woman in Nebraska elected to serve a full Senate term. “Yes, it’s very historic. I didn’t think it was when I was running,” she said. The significance began to dawn on Fischer, she recalled, when women began bringing their daughters to pose for pictures with her.

Four other states — Hawaii, Massachusetts, North Dakota and Wisconsin — also elected women to the Senate for the first time.

Among its female membership, the new Congress will see many other firsts, according to an analysis of election results released Wednesday by the Center for American Women and Politics.

Wisconsin’s Tammy Baldwin will be the first openly gay person in the Senate.

Hawaii’s Mazie Hirono will be the first Asian American woman and only the second nonwhite woman there. And in the House, fellow Hawaiian Tulsi Gabbard will be the first Hindu in Congress.

Women cracked the glass ceiling further down the ballot, as well. With the election of Republican Katrina Shealy to the South Carolina state Senate, for instance, there is no longer an all-male state legislative chamber anywhere in the country, the Rutgers center reported.

All of these milestones come at a time when many women’s advocates had begun to worry that the advances they had made since the early 1990s were beginning to stall.

The election of 1992 had been deemed the “year of the woman.” That year, many women were outraged over the Senate’s confirmation of Clarence Thomas to the Supreme Court despite claims of sexual harassment lodged against him by Anita Hill, at the time a law professor at the University of Oklahoma.

After the 1992 election, the number of women in the Senate doubled, and the number in the House went from 28 to 47.

While many hoped it was the beginning of a surge in female officeholders, the gains had been smaller in recent election cycles. After the 2010 midterm contests, the number of women in the House dropped for the first time in more than 30 years, by one seat.

At 16.8 percent of the House, women’s representation in the U.S. legislature last year ranked 78th in the world, tied with Turkmenistan, according to statistics compiled by the Inter-Parliamentary Union.

In the Senate, a record 17 women served, but that number had remained steady since 2009.

And with the retirement of two senior women — Republicans Olympia J. Snowe of Maine and Kay Bailey Hutchison of Texas — it had appeared possible that the number of women in the Senate would shrink in 2013.