(CNN) The 116th Congress officially convened Thursday. In this new Congress, Democrats have taken control of the US House of Representatives, while Republicans continue to hold their majority in the US Senate. Dozens of senators and representatives made historic firsts as they were sworn in.
More than a dozen documents and books -- including the US Constitution, the Eastern Orthodox Bible and the Quran -- were used to swear in officials of various ethnic and religious traditions.
Democrats Rashida Tlaib of Michigan and Ilhan Omar of Minnesota are the first Muslim women elected to serve in Congress.
Women across the country wore traditional Palestinian clothing to honor Tlaib's arrival on Capitol Hill.
On the eve of also becoming the first Somali-American member of Congress, Omar celebrated returning to the same Washington-area airport where she first arrived in the United States as a refugee.
Returning Republican Rep. Brian Mast of Florida welcomed two other combat veterans to the US House with a tweet that helped illustrate the sacrifice the lawmakers had made.
Democrat Ayanna Pressley became the first black congresswoman to represent Massachusetts.
Republican Marsha Blackburn became the first female senator from Tennessee.
Democrats Veronica Escobar and Sylvia Garcia became the first Latinas to represent Texas in Congress.
Democrat Debbie Mucarsel-Powell of Florida became the first Ecuadorian-American, as well as the first South American immigrant, sworn into Congress.
Democrat Kyrsten Sinema became the first female senator elected to represent Arizona. Sinema also made history as the first openly bisexual senator.
Kansas and New Mexico sent the first Native American women to Congress.
Abigail Spanberger, a former CIA officer who ran on expanding health care coverage with a public health insurance option, is the first woman to represent Virginia's 7th District.
Pelosi became the first person to return to the position of House speaker since the legendary Sam Rayburn.