We will continue to cover the story with analysis and more reaction onbbc.com/news
- The Republican Party has taken control of the Senate by picking up at least six seats from the Democrats
- They have also strengthened their grip on the House of Representatives
- Ballot initiatives expanding marijuana use and increasing minimum wage passed in some states
- The economy, government dysfunction and President Obama's unpopularity were key issues
This concludes our coverage of the US mid-term elections on a night of major wins for Republicans in the Senate and some surprising upsets in state governor races.
Most polls in Alaska are now closed. The last Senate race of the night will be determined there.
Democrat John Barrow had held his Georgia Congressional seat since 2004, but his defeat tonight marks the end of an era for his party's Southern history.
But inan editorial on Foxnews.com, Douglas Schoen says Republicans "got everything they wanted Tuesday night - and more".
He added: "This election represents a complete rejection of the president, his agenda and his leadership".
The US media is digesting the news of a resounding night for the Republicans.
"Virtually every Republican candidate campaigned on only one thing: what they called the failure of President Obama," saysa New York Times editorial, which condemns what it calls a negative Republican campaign.
BBC News, Washington
Just to recap, the Republicans have swept to power in the Senate and strengthened their grip on the House, meaning they control both chambers of Congress for the first time since 2006.
Capitalising on voter dissatisfaction with the direction of the country, and the unpopularity of President Obama, they picked up seats in West Virginia, Montana, South Dakota, Colorado, North Carolina, Iowa and Arkansas.
This years mid-term election resulted in some history being made at the national and state levels.
"We are humbled by the responsibility the American people have placed with us, but this is not a time for celebration," House Speaker John Boehner says in a statement.
"Americans can expect the new Congress to debate and vote soon on the many commonsense jobs and energy bills that passed the Republican-led House in recent years with bipartisan support but were never even brought to a vote by the outgoing Senate majority, as well as solutions offered by Senate Republicans that were denied consideration."
Former Democratic governor of New Mexico, Bill Richardson, says Democrats have been let down today by poor turnout in key Latino states such as Colorado, Florida and Arizona. He's beentelling BBC World Service that Latinos are upset over President Obama's slow progress on immigration reform.
Supporters of Senator-elect Joni Ernst cheer as results come in
There was one spot of bad news for Republicans on an otherwise successful night - incumbent governor Tom Corbett has lost to Democrat Tom Wolf in Pennsylvania. But Maryland Lt Governor Anthony Brown is in trouble in his race for the governor's seat in normally Democrat-safe Maryland.
Oregon's ballot measure to legalise the sale and possession of marijuana has passed. The state joins the District of Columbia in approving pot-legalisation initiatives. Although a majority of Florida voters also voted in favour of legalisation today, it did not break the 60% support level necessary for passage there.
The Huffington Post's Hunter Stuarthas an interesting look at what Oregon's move means for neighbouring Washington state, which passed its own legalisation two years ago, including what significantly lower taxes on the drug in Oregon means.
The Vermont governor's race is close, but neither Governor Peter Shumlin nor challenger Scott Milne gained more than 50% of the vote. But there is no run-off - and the Vermont legislature will now pick the governor.
Colorado GOP Governor Bill Owens told BBC World Service Republican gains in the midterms are "fairly sweeping" and a denunciation of President Obama's agenda. He predicted Republican control of both Houses of Congress would put American politics back on a more moderate path.
Democrat Tom Udall wins re-election to his Senate seat in New Mexico.
The Republican response has been swift, with national chairman Reince Priebus congratulating his candidates.
"The American people have put their trust in the Republican Party, sending a GOP majority to the US Senate... our party's principles and message resonated with voters across the country. This was a rejection of President Obama's failed polices and Harry Reid's dysfunctional Senate."
Chad Pergram, Fox News
And the night is fast getting better and better for the Republicans. ABC News projects Joni Ernst has beaten Bruce Braley in Iowa - which would bring the Republican majority to 52.
More Republican joy in Georgia where Nathan Deal has won the governor race, beating Democrat Jason Carter, grandson of former president Jimmy Carter.
Republicans have won control of the Senate with a win by Thom Tillis over Kay Hagan in North Carolina.
On CNN, Washington correspondent Jake Tapper notes - "It looks like for the first time in history, 100 women are in the House".
Former Texas Republican Senator Kay Bailey Hutchison tells the BBC World Service the party needs to have a better message on immigration if they want to capture the Hispanic vote in 2016.
Another Senate result - Pat Roberts has fended off a challenge from independent Greg Orman in the very closely watched race in Kansas.
The Associated Press news agency confirms David Perdue wins the Georgia senate race, as Michelle Nunn concedes in front of a crowd of supporters.
The BBC's Jon Kellyoutlined some scandal-hit politicians who looked poised to win re-election. Scott DesJarlais, a doctor who campaigned on pro-life issues but pressured his wife and mistress to terminate pregnancies, has won his bid for re-election in Tennessee. So too has Michael Grimm, the Staten Island congressman who is facing 20 criminal counts.
The District of Columbia voters approve a ballot initiative legalising the possession of small amounts of marijuana for personal use. As Vox's German Lopez points out, however,the US Congress still has an opportunity to review - and reject - the measure before it becomes law in the nation's capital.
The first results from the West Coast have begun - Democrat Jerry Brown is re-elected governor in California.
While they may not be representative of all Americans, exit polls do provide some useful insight into the minds of voters. Today's polls show voters are deeply pessimistic about the direction of America and its politics.
Results coming thick and fast now. Wisconsin Governor Scott Walker has won re-election. As Rajesh Mirchandaniexplains in a video outlining what tonight's results could mean for the 2016 presidential election, Mr Walker is among the many Republican named as possible presidential candidates for 2016.
CNN and ABC are projecting Republican David Perdue to win against Democrat Michelle Nunn. It is not a pick-up seat for the Republicans but there were hopes among Democrats they could steal it and this will further weaken then chances of retaining their majority.
Meanwhile in Virginia, Democrat Mark Warner is neck-and-neck with Republican Ed Gillespie. Mr Warner leads by only 3,400 votes out of more than two million votes, with 99% precincts reporting. The result has confounded expectations as even the Republican party officials had not expected the race to be this close.
NPR social media editor Wright Bryantweets: "Who's the youngest of them all? Saira Blair, 18, is ready to make a difference in West Virginia". She is now the youngest elected state house representative.
Mr Gardner attacked his opponent for voting with President Obama.
Given Colorado's recent Democratic momentum in presidential elections, Republicans had been watching the race closely as as a test case for whether traditional rural conservatives like Mr Gardner can still win state-wide elections in places, such as Colorado, that seem to be slipping out of their grasp, the BBC's Anthony Zurcherwrote after visiting Colorado in September.