The 2018 US midterm elections could change the course of the country entirely.
The House of Representatives had all 435 seats up for grabs, along with 35 seats in the 100-member Senate, and 36 governorships. The Democrats needed to gain 23 seats to win the House majority, and polls suggested they had a good chance.
But Republicans had a 51-49 edge in the Senate and were favoured to hang on to their power since Democrats were defending 26 seats compared to Republicans defending only nine.
Which party took the crown? Here's what went down.
6:33pm - US President Donald Trump has reportedly called House minority leader Nancy Pelosi to congratulate her for the Democrats taking over power of the House of Representatives.
6:10pm - "Thanks to you tomorrow will be a new day in America," Nancy Pelosi said, thanking volunteers after it was projected that Democrats will take over control of the House of Representatives.
In the House, Democrats picked up seats across the map, ousting incumbent Republican Barbara Comstock in suburban Virginia and sending Donna Shalala, a former Cabinet secretary under President Bill Clinton, to the House in south Florida, Reuters reports.
But in the Senate, where Republicans were heavily favoured to keep control heading into voting, Republican Mike Braun captured Democrat Joe Donnelly's seat in Indiana and Republican Kevin Cramer beat Democratic Senator Heidi Heitkamp in North Dakota.
5:44pm - House minority leader Nancy Pelosi has spoken after democrats gained House control. "We will honour the vision of our founders: having a legitimate debate, but honouring that we are one country," she said.
"Thanks to you we owned the ground," she told those assembled Democrats, "thanks to you tomorrow will be a new day in America. Remember this feeling, know the power to win," she added.
5:35pm - The Democrats are projected to gain a vast majority in the House of Representatives. With a majority, Democrats will be able to mount investigations that could dampen the President's confidence during his tenure. Nevertheless, Mr Trump says the results have been a "success".
5:30pm - US President Donald Trump has spoken about the midterm results, calling them a "tremendous success" on Twitter. It comes after it was projected that Republicans will keep their majority in the Senate.
5:19pm - Americans have voted in the first two Muslim women to serve in the US Congress - one a former refugee who fled Somalia's civil war and a Detroit-born Palestinian-American, Reuters reports.
Democrat Ilhan Omar, a 36-year-old who ran for Minnesota's 5th congressional district, is a Somali refugee who fled the civil war. Meanwhile, 42-year-old Rashida Tlaib has run for Michigan's 13th congressional district. She's a Detroit-born Palestinian-American.
5:08pm - Democrats are projected to win the House of Representatives, CNN and other sources have reported. It will gain the Democrats new powers to challenge President Trump for the next two years of his presidency.
With a House majority, Democrats will have the power to investigate Trump's tax returns and possible conflicts of interest, and challenge his overtures to Saudi Arabia, Russia and North Korea, Reuters reports.
5:04pm - It looks as though Republican Brian Kemp could triumph over Democrat Stacey Abrams in the Georgia gubernatorial race. Mr Kemp is Georgia's current Secretary of State, and he's come under fire for allegations of suppressing votes of black Americans.
4:47pm - Republican Ted Cruz has held his Senate seat in Texas, narrowly beating Democrat Beto O'Rourke. Mr Cruz has been a senator since 2013. It's a tough blow for the Democrats, as other states such as Tennessee and North Dakota have been won by Republicans for the Senate.
"We saw a hundred-million dollar race with Hollywood coming in against the state, with the national media coming in against the state, but all the money in the world was no match for the good people of Texas," Mr Cruz said, with reference to his opponent.
However, Democrat Tammy Baldwin has held on to her Senate seat in Wisconsin, AP reports, as has Joe Manchin in West Virginia, Bob Casey in Pennsylvania and Sherrod Brown in Ohio.
4:24pm - CBS News says Republicans will maintain control of the Senate, multiple sources have projected. Meanwhile, Fox News has projected that Democrats will win control of the House.
4:13pm - Democrat Jared Polis has been elected as the first openly gay governor in the United States. He won the gubernatorial race in Colorado, a state known for being conservative.
4:06pm - Current election results for the Senate put Republicans at 46 percent, ahead of 38 percent for Democrats, according to the Associated Press. Of the 100 seats in the Senate, 85 have been declared.
Republicans are also currently ahead of Democrats in the House of Representatives race. AP puts Republicans at 23.2 percent with 101 seats of out 435 so far, while Democrats currently only have 86 seats.
3:53pm - Alexandria Ocasio-Cortez has won the congressional race in New York's 14th district, well ahead of her Republican opponent Anthony Pappas and Working Families Party candidate Joe Crowley. CNN reports she's the youngest woman elected to Congress.
3:48pm - Democrats have flipped another House seat in Florida. Republican Carlos Curbelo of Miami has conceded defeat to Democrat Debbie Mucarsel-Powell. The New York Times reported on the candidate here.
3:35pm - The Democrats have suffered a blow in the race to win back the Senate. Republican Mike Braun has defeated Democrat Joe Donnelley in the Indiana Senate race, AP reports. Most projections have pointed to Republicans securing the Senate, so it's no surprise.
3:30pm - Democrat Andrew Cuomo will keep his role as governor of New York by a large margin, AP reports, while Republican Greg Abbott will keep his role as governor of Texas, but only by a slim margin.
2:54pm - Democrats have flipped their second seat in the House of Representatives in Florida, after flipping a seat in Virginia. Democrat Donna Shalala has declared victory over her Republican opponent, Maria Elvira Salazar in the Miami-area 27th district.
2:44pm - Vice President Mike Pence is set to have a family member join him in Washington, DC. His brother, Republican Greg Pence, has won election in Indiana's 6th congressional district, beating Democrat Jeannine Lake.
2:39pm - Democrats win re-election of Gina Raimondo for governor of Rhode Island.
2:30pm - Ayanna Pressley has made history as the first black member of the House of Representatives from the US state of Massachusetts. She has defeated her Republican opponent Michael Capuano.
2:22pm - According to the latest results from the Associated Press, Republicans currently hold 42 percent of the Senate seats, while Democrats hold 31 percent. Meanwhile, Republicans currently hold 5.3 percent of the House seats while Democrats hold 6 percent.
But only 49 of the 435 House seats have been announced so far. The Senate picture is more clear, with 74 out of 100 seats declared so far.
2:16pm - AP projects Democratic senator Sherrod Brown will fend off a challenge for his seat in Ohio - a state which President Trump won by eight points in 2016. Also hoping to return to the Senate for the Democratic Party is Elizabeth Warren, a potential 2020 presidential candidate.
2:04pm - Meanwhile, the Democrats have held a seat in a battleground race in Florida. The Associated Press projects Democrat Stephanie Murphy will win re-election to the House in Florida's 7th congressional district.
1:51pm - The Democrats have flipped their first House seat in Virginia. Democrat Jennifer Wexton has won the seat from Republican Barbara Comstock.
1:44pm - Florida's Senate seat is looking secure for Democrats with a third of the vote in, 50.7 percent to 49.3 percent. For Indiana's Senate seat, however, Republican Mike Braun is ahead, 58 percent to 37 percent, results shows. But only 14 percent of votes have been counted so far.
1:30pm - Hillary Clinton has tweeted her support for Georgia's Democrat gubernatorial candidate Stacey Abrams.
1:07pm - Latest wins (AP):
What's a congressional district? A congressional district is an electoral constituency that elects a single member of a congress.
- Democrat Bobby Scott has won re-election to the US House in Virginia's 3rd congressional district
- Democrat John Lewis has won re-election to the US House in Georgia's 5th congressional district
- Republican Austin Scott has won re-election to the US House in Georgia's 8th congressional district
- Independent Bernie Sanders has won re-election to the US Senate in Vermont
- Democrat Tim Kaine has won re-election to the US Senate in Virginia
- Republican James Comer has won re-election to the US House in Kentucky's 1st congressional district
- Republican Daniel Webster has won re-election to the US House in Florida's 11th congressional district
- Republican Ted Yoho has won re-election to the US House in Florida's 3rd congressional district
- Republican Bill Posey has won re-election to the US House in Florida's 8th congressional district
1pm - The White House has released a statement. It says President Trump has "energised a staggering number of Americans at packed arenas and in overflow crowds at rallies across the country."
"Under President Trump's leadership, the Republican National Committee has raised more than a quarter billion dollars, fueling an extraordinary ground game geared toward defying midterm history and protecting the GOP's majorities," it says.
"Tonight, we can continue down the path of American prosperity and security or we can go backwards."
12:55pm - (Reuters) The remainder of the polling locations in Indiana and Kentucky, and in half a dozen other states, will close in another hour. But it could be hours before the winners are determined in dozens of tight races that will decide control of the House of Representatives and Senate.
12:40pm - Republican Hal Rogers has won re-election to the US House of Representatives in Kentucky's 5th congressional district, the Associated Press reports.
12:40pm - 2018 Georgia gubernatorial candidate Stacey Abrams has reflected on her rocky campaign. On social media, she said she's met voters all across the state, to share her vision of affordable and accessible health care.
The US states of Florida and Georgia have been mired by racist political campaigns to undermine two candidates who could become the first African-American governors of those states.
An automated phone call claiming to be from US celebrity Oprah Winfrey called Ms Abrams "a poor man's Aunt Jemima", referencing a controversial black woman stereotype from the slavery-era known as "mammy".
12:33pm - The latest Rasmussen Reports/Pulse Opinion Research poll puts President Trump's overall approval rating at 48 percent.
12:26pm - Some official early voting numbers - not exit poll numbers - have come in from the US state of Iowa. They show Democrats up 19.1 percent compared to 2014.
12:22pm - Despite the majority of voters saying they have voted against Donald Trump in a CNN exit poll, CNN says most voters feel confident about the economy under the President's direction. More than two-thirds said the economy is excellent or good.
12:14pm - The next round of polls will close at 7:00pm ET (1pm NZ time), NBC News reports. That list includes the remaining parts of Kentucky and Indiana, Georgia, most of Florida, New Hampshire, South Carolina, Vermont and Virginia.
12:08pm - The first polling stations to close have done so in Kentucky and Indiana, the Guardian reports.
11:55am - US singer Beyonce has voiced her support for Democrat Beto O'Rourke who is running against Republican Senator Ted Cruz in one of the nation's most anticipated and closely-watched races.
11:35am - First Lady Melania Trump has broken her silence on the midterms. She tweeted her support for the Republican Party, saying "Vote Red".
11:33am - (Reuters) Voter turnout in national elections, normally lower when the White House is not at stake, could be the highest for a midterm election in 50 years, experts predicted.
About 40 million early votes were likely cast, said Michael McDonald, a professor at the University of Florida who tracks the figures.
11:25am - More people have voted against Donald Trump than for him, a CNN national exit poll shows. About three-in-10 said they strongly approve of Mr Trump while almost half said they strongly disapprove of him.
11:20am - (Reuters) Problems with voting machines were preventing some Americans from casting ballots in a dozen states, US rights advocates said, following complaints about registration problems, faulty equipment and intimidation they have received throughout early balloting.
But a Department of Homeland Security official said the reports of voting technology failures appeared so far to have had no significant impact in preventing people from voting.
11:15am - There are reports that electronic machine readers have broken in some voting booths, so voters have been instructed to use paper ballots.
NYC Votes told citizens on Twitter to report broken scanners and any issues with voting, urging people not to be discouraged.
"Your voice matters and your vote counts," it said.
11pm - There are fears voter suppression has stopped US citizens from voting in the midterms.
A blogger posted footage to social media showing people lining up in the US state of Georgia waiting for their turn to vote.
But the blogger says officials "did not supply power cords for their voting machines at a polling site in a mostly African-American neighbourhood".
"The batteries died and people [waited] for house," he says.
"This is voter suppression y'all."
The Associated Press reported last month that 53,000 voter registrations - 70 percent of them from black applicants - were being held by the office of Georgia gubernatorial candidate Brian Kemp.
The applicants had apparently failed to meet registration information - an apparent move to block their votes for Mr Kemp's opponent Stacey Abrams.
10:30am - In the last few hours, US President Donald Trump has been tweeting his support for congressional candidates he wants to win, as some perceive the midterms as a referendum on his presidency.
He tweeted his support for Republican Illinois candidate Randy Hultgren who's up against Democrat Lauren Underwood for a seat in the US House of Representatives. Mr Trump said Mr Hultgren has his "Total Endorsement!"
The President also tweeted his support for Florida Republican candidate Michael Waltz who's up against Democrat Nancy Soderberg. Mr Trump said Mr Waltz has his "Strong Endorsement!"
The polls for the Florida vote close at 1pm NZ time, while the polls for the Illinois vote close at 2pm.
10:00am - The first results from the US midterm elections are expected to be announced at 1pm in New Zealand. Most polling stations close at around 8pm ET on the East Coast, that's 2pm in New Zealand. While a few states close later on the West Coast with Alaska being the last at 1am ET (7pm NZT).