New US legislators were sworn in on Thursday, with a number of "firsts" taking their seats in the 116th Congress.
Democrats assumed majority control of the House of Representative, while Republicans kept their hold on the Senate.
Nancy Pelosi, who was elected speaker of the House, said in a USA Today interview that US President Donald Trump should expect a "different world" with the new Congress.
Among those sworn in is a record number of women, including the first Muslim women, as well as the youngest woman ever elected to Congress.
Here's a look at the 'firsts' taking their seats:
Rashida Tlaib and Ilhan Omar
First Muslim women elected to Congress
Both Rashida Tlaib and Ilhan Omar won in their Democrat-safe seats becoming the first Muslim congresswomen.
Tlaib was born in Detroit to Palestinian immigrant parents, and Omar arrived in the United States as a young girl from a refugee camp in Kenya after fleeing civil war in Somalia.
Omar is also the first Somali American to serve in the US Congress.
Alexandria Ocasio-Cortez
Youngest woman elected to Congress
Alexandria Ocasio-Cortez beat 10-term incumbent Joe Crowley in the Democratic primary for New York's 14th District and has now made history as the youngest woman to join Congress.
Born to a father from South Bronx and a mother from Puerto Rico, Ocasio-Cortez was an organiser for the 2016 Bernie Sanders presidential campaign.
Deb Haaland and Sharice Davids
First Native American women elected to Congress
Deb Haaland, a member of the Pueblo of Laguna tribe, is the first Native American woman elected to Congress, alongside Sharice Davids.
Haaland said she will prioritise climate change, as well as a number of other progressive issues, such as Medicare-for-all and debt-free education.
Davids is a Cornell Law School graduate and professional Mixed Martial Arts fighter, who was raised by a single mother.
She is a member of the Ho-Chunk Nation, a Native American tribe that hails from Wisconsin.
The former White House fellow under Obama, is openly gay and an advocate for LGBT issues. She was elected to the third congressional district in Kansas.
Ayanna Pressley
Massachusetts's first black congresswoman
Democrat Ayanna Pressley surprised many when she upset 10-term incumbent Michael Capuano during Massachusetts's 7th Congressional District primary.
Veronica Escobar and Sylvia Garcia
Texas's first Latina congresswomen
In a state with a Hispanic population of close to 40 percent, in 2018 Veronica Escobar and Sylvia Garcia became the first women of Latin American origin to represent Texas in the House of Representatives.
Escobar was elected to Texas's 16th District, while Garcia won the state's 29th District.
Jahana Hayes
First African American woman from Connecticut elected to Congress
Jahana Hayes, a former teacher, made history in Connecticut when she won her state's fifth congressional district, becoming Connecticut's first African American woman elected to Congress.
Marsha Blackburn
Tennessee's first female senator
In a closely-watched race, Tennessee voters elected Republican Marsha Blackburn to the US Senate, making her the first female to serve in the chamber from the state.
Cindy Axne and Abby Finkenauer
Iowa's first women elected to the House
Abby Finkenauer and Cindy Axne became Iowa's first female representatives after defeating their Republican male competitors in November.
