Among the historic class of new congresspeople who took the oath of office in the US House of Representatives on Thursday are the first Native American women, the first Muslim women, the first black women elected from Massachusetts and Connecticut, the first Hispanic women elected from Texas, and the youngest woman to be elected to Congress.

There is a former NFL linebacker, a doctor and a climate scientist. There are a number of former members of the military and intelligence services, many of them women. There are seasoned veterans of past presidential administrations and a handful of political neophytes who never held office before running for Congress in 2018.

A record 102 women were sworn into the House on Thursday, 35 of whom were elected for the first time in November in a historic wave of success for female candidates.

“We’re in the building. Swearing in tomorrow,” the congresswoman-elect Alexandria Ocasio-Cortez of New York captioned a photograph of her and five incoming female colleagues, posing in the US Capitol.

The arrival of this large new group will significantly alter the balance of power in Washington, where the federal government is currently paralysed by a shutdown stretching into its 13th day.

Democrats regained control of the House on Thursday eight years after losing power. Their takeover was fuelled by 63 Democrats whose victories in the November midterm elections helped the party win by the largest margins since the Watergate scandal in 1974.

Nancy Pelosi reclaimed her former title as speaker of the House. She made history in 2007 as the first woman to hold the position, before handing over the gavel when the GOP won the House in 2011. The Republicans will be led by Kevin McCarthy of California.

Nancy Pelosi reclaimed her former title, House speaker, on Thursday. Photograph: Kevin Lamarque/Reuters

“I think of it is a responsibility,” Pelosi told Today when asked how she felt about being the most powerful woman in Washington. “I don’t think of it as an accomplishment … This isn’t breaking a glass ceiling – this is breaking a marble ceiling in the Capitol of the United States.”

“I think of it is a responsibility. I don’t think of it as an accomplishment… This isn’t breaking a glass ceiling – this is breaking a marble ceiling in the Capitol of the United States.” @NancyPelosi responds to being “most powerful” woman in U.S. government pic.twitter.com/l1Zfcguupd — TODAY (@TODAYshow) January 3, 2019

Pelosi became one of few elected officials to regain the gavel, and the first for more than 50 years.

“When our new members take the oath, our Congress will be refreshed and our democracy will be strengthened by the optimism, idealism and patriotism of this transformative freshman class,” Pelosi said on Thursday. “Working together, we will redeem the promise of the American dream for every family, advancing progress for every community.”

As in years past, proud relatives and curious members of the public filled the House and Senate galleries as the 116th Congress was sworn in and new leaders were elected. But this year the faces look different – more diverse and more female.

Rashida Tlaib, an incoming Democratic congresswoman from Michigan, announced on Instagram that she would wear a traditional Palestinian thobe – a long-sleeved, ankle-length garment – when being sworn in. Ilhan Omar, an incoming Democratic congresswoman from Minnesota, swore the oath of office on her grandfather’s Qur’an.

In an Instagram post, her father recounted the family’s journey from a refugee camp in Kenya to the US, where they first arrived at an “airport in Washington DC”.

“I could never have dreamed that 23 years later I would return to the same airport with my daughter Ilhan by my side, the day before she is to be sworn in as the first Somali-American elected to the United States Congress,” he wrote.

Congressman Jim Langevin, a Democrat from Rhode Island and the first quadriplegic person elected to Congress, presided over the chamber on the first day.

After the speaker was elected, the newly empowered Democratic majority was due to vote on an internal rules package designed to bring more transparency to congressional governance, a measure that has already exposed ideological tensions within the party. Two prominent progressives, Ocasio-Cortez and Congressman Ro Khanna of California, said they would oppose the package, arguing that the rules would hinder liberals’ ability to advance their ambitious social agenda.

Democrats will then turn to their first major order of business: a spending package that would end the government shutdown.

The party is unified on the legislation but Donald Trump has said he will refuse to sign the bill, which does not include funding for his border wall.

The vote will be the first test of their power – and an indication of the battles to come in a newly divided government.