Key states: battlegrounds that proved crucial as the election drama unfolded
West Virginia: Donald Trump won West Virginia's 3rd district by 30 points. But it is the Democratic candidate running in the district, which has a long history of coal mining, that is gaining national attention.
Richard Ojeda says he voted for Mr Trump in 2016, opposes universal background checks for gun buyers, and is pro-coal.
Mr Ojeda was running against Republican Carol Miller in the open-seat race after the incumbent Republican Evan Jenkins vacated the seat to run for the Senate. Analysts kept a close watch to see if a populist Democrat in a pro-Trump area is a winning formula. It wasn't. Ms Miller was projected to defeat Mr Ojeda.
Republican Representative Mimi Walters was battling to keep hold of her seat against Democrat Katie Porter in the state's 45th district, Orange County. The number of registered Republicans in the county has consistently declined as its population becomes more diverse.
Ms Walters was one of seven Republicans representing districts in California which Hillary Clinton won in 2016. The Democrats needed to take several of these in order to regain a majority in the House.
Pundits were viewing a win in this race as a sign they will do well across southern California - picking up crucial Republican-held seats. But with almost half the votes counted, Ms Walters was in the lead.
Minnesota's 8th district was considered one of the Democrats' most at-risk seats in November. It is a traditionally Democrat area - former president Barack Obama won the district twice but it swung heavily to Donald Trump in the 2016 election.
Democrat candidate Joe Radinovich, a former state legislator, was facing a tough battle against Republican Pete Stauber, a county commissioner, and the Republican ended up defeating his opponent.
The race in Texas' 23rd district largely focused on one of the Trump administration's main concerns - immigration. The district contains a third of the US-Mexico border and has the second highest population of 'Dreamers' - the term given to undocumented migrants who arrived in America as children and have been granted temporary protection.
The incumbent, Republican Will Hurd, was a former CIA agent who has chosen to distance himself from Mr Trump. His Democratic rival, Gina Ortiz Jones, was a Filipina-American, openly LGBTQ and an Iraq veteran. Mr Hurdwas tipped to win by a narrow margin and, with more than 85pc counted, he was projected to fend off his Democratic rival.
Moderate Republicans were looking to Florida's 26th district to see whether they could keep hold of a largely Hispanic area.
The incumbent, Carlos Curbelo, was well-liked but Republicans feared his Democrat opponent, Latin immigrant Debbie Mucarsel-Powell, could sweep to a surprise victory. Ms Mucarsel-Powell proved their fears well-founded, defeating her rival.