(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.

Pelosi swears in members of the 116th Congress.

From left to right, Democratic US Reps. Alexandria Ocasio-Cortez, Barbara Lee, Annie Kuster and Jan Schakowsky take a selfie on the House floor.

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.

Various faiths are represented by the holy books House members used to take their oaths of office.

Democrats Rashida Tlaib of Michigan and Ilhan Omar of Minnesota are the first Muslim women elected to serve in Congress.

Rep. Rashida Tlaib of Michigan votes for Pelosi as House Speaker as one of her children "dabs."

Women across the country wore traditional Palestinian clothing to honor Tlaib's arrival on Capitol Hill.

Rep. Ilhan Omar of Minnesota celebrates with her children after taking her oath of office.

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.

23 years ago, from a refugee camp in Kenya, my father and I arrived at an airport in Washington DC. Today, we return to that same airport on the eve of my swearing in as the first Somali-American in Congress. #Hope #Ilhan 🙏🏾 pic.twitter.com/jVeP3DOipN

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.

And just like that, with my hand on grandad's bible, it's official: @RepPressley. Follow along for official updates from our Congressional office. I am so honored to serve the MA 7th. And don't worry I'll still be right here at @AyannaPressley too. Let's get to work. pic.twitter.com/yKr5P6l8Rd — Ayanna Pressley (@AyannaPressley) January 4, 2019

Republican Marsha Blackburn became the first female senator from Tennessee.

It is an honor to be sworn in today to represent Tennessee in the United States Senate by Supreme Court Justice Brett Kavanaugh alongside @SenAlexander and @SenBobCorker. pic.twitter.com/ei71osonI1 — Marsha Blackburn (@MarshaBlackburn) January 3, 2019

Democrats Veronica Escobar and Sylvia Garcia became the first Latinas to represent Texas in Congress.

It was fun to see my husband so excited about getting his spouse pin. And with all the sacrifices he made to help me get here, he sure does deserve it. Congrats on your "pledge pin," honey! 😄❤️ #116thCongress pic.twitter.com/k66NPFdiLf — Rep. Veronica Escobar (@RepEscobar) January 3, 2019

Democrat Debbie Mucarsel-Powell of Florida became the first Ecuadorian-American, as well as the first South American immigrant, sworn into Congress.

Can't imagine a better crew to join me for swearing in! pic.twitter.com/0n4BdhqErp — Debbie Mucarsel-Powell (@DebbieforFL) January 3, 2019

Democrat Kyrsten Sinema became the first female senator elected to represent Arizona. Sinema also made history as the first openly bisexual senator.

Kyrsten Sinema is sworn in by Vice President Mike Pence.

Kansas and New Mexico sent the first Native American women to Congress.

Democratic Reps. Deb Haaland and Sharice Davids embrace on the House floor.

New Mexicans are in the house, the US House that is. #116thCongress pic.twitter.com/imeeaVJAkq — Congresswoman Deb Haaland (@RepDebHaaland) January 3, 2019

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.

On our way to the swearing-in! I am excited to begin officially representing #VA07 in the U.S. House. pic.twitter.com/kQLSzQyhVU — Abigail Spanberger (@SpanbergerVA07) January 3, 2019

Pelosi became the first person to return to the position of House speaker since the legendary Sam Rayburn.