The 29-year-old comfortably beat her Republican opponent, Anthony Pappas, to win in New York's 14th District.
The campaigning from both sides of politics was polarising, with the Republicans maintaining an anti-immigration and America-first message, while the Democrats pledged to put an end to divisionary politics. "History has been made and we're never going back". Haaland said on Twitter.
Tlaib is the daughter of Palestinian immigrants and became the first Muslim female member of Michigan's state legislature a decade ago. Democratic women flipped three Republican-held seats: Mary Lou Scanlon, Chrissy Houlahan, Susan Wild, and Madeleine Dean won an open seat. According to VoteCast, women voted considerably more in favour of their congressional Democratic candidate.
Democratic senators Claire McCaskill of Missouri and Heidi Heitkamp of North Dakota lost their races, while Republican representative Marsha Blackburn became the first woman elected to the US Senate from Tennessee. In New Jersey, Democratic Gov. Jim McGreevy, elected in 2001, had been outed as gay while in office.
American voters have elected many men in their 20s to Congress, but Ocasio-Cortez could become the youngest woman to join the House.
There was also a historic gender gap that showed women more supportive of Democrats than Republicans.
Two women helped Democrats pick up seats in Florida: Debbie Mucarsel-Powell and Donna Shalala, a member of former President Bill Clinton's Cabinet.
Before Tuesday's elections, women made up a record 20% of Congress - 23% of the Senate and 19% of the House.
"Nothing is more wholesome for our country, for our politics, for our campaigning than the increased participation of women in the electoral process", Nancy Pelosi, who's on track to be Democrats' pick for speaker of the House, said last month on CNN. According to data compiled by The Associated Press, 237 women ran for the House as major-party candidates this year.
It was the culmination of two years of anger, frustration and activism driven by women appalled by Donald Trump's election and presidency.
OLATHE, KS - NOVEMBER 06: Democratic candidate for Kansas' 3rd Congressional District Sharice Davids speaks to supporters during an election night party on November 6, 2018 in Olathe, Kansas. It was the first time Crowley faced a serious primary challenge in 14 years and marked an incredible victory for Ocasio-Cortez. Tlaib's campaign priorities included enforcing a $15 minimum wage, standing up for unions and making tuition at public colleges, universities and trade schools free for working families.
"I am so honoured to share both the ballot and the stage with the many visionary, bold women who have raised their hand to run for public office", said Ayanna Pressley, who became the first black woman elected to Congress from MA.