Senate majority leader Mitch McConnell makes an acceptance speech after winning re-election in Kentucky.

The top Republican's seat was never really in question. Kentucky went for Trump by 30 points in 2016, and as we reported a bit earlier, is projected to be a win for Republicans once again.

Image source, Reuters

Donald Trump wants to "project strength" and "set his own narrative" tonight, a senior Trump campaign official who spoke to the president has told CBS, our partner network in the US.

"Yes, the president will speak tonight. Even if it's not to declare victory, he needs to set the narrative," the official said.

Trump will deliver remarks from the White House East Room, the official added.

A number of senior advisers say there is frustration over Democratic talk of the "red mirage" - referring to the idea that the early projections of Trump winning in some states are misleading because they don't yet include postal ballots, which tend to lean towards Democrats (red is the colour of the Republicans).

There's a sense that the president cannot lose hold of tonight's story, the official says.

Image source, Getty Images

Why does Iowa matter and when will we know who’s won?

In 2016, Donald Trump won the Midwestern state of Iowa with a huge electoral swing.

He beat Hillary Clinton by over 9% in a state previously won twice by Barack Obama.

Trump took Iowa’s six electoral college votes with a promise to bring back jobs to the state, appealing to many who’d traditionally voted for Democratic candidates.

This time around polls suggest Trump is slightly ahead in the state, but the vote could easily go either way.

Early votes are already being counted and election officials are confident they will have a result on the night.

However, postal ballots that arrive by 9 November (and that are postmarked no later than 2 November) are also to be counted.

The polls in Iowa closed at 22:00 ET (03:00 GMT).

Polls are closing in a few minutes in Iowa (6 electoral votes), Montana (3); Nevada (6) and Utah (6).

Not a lot of electoral college votes are on the table in these states, but either candidate will need all they can get to reach the necessary 270.

You can always check the state of the race by looking at the latest tally at the top of this page.

Image source, Getty Images

Results for the Georgia county that includes Atlanta - the state's capital and its most populous city - will be delayed after a water pipe burst in a room with absentee ballots, the Atlanta Journal-Constitution reports.

No ballots were damaged, voting officials say, but the incident has delayed counting by around four hours, dashing hopes of reported results by around 23:00 ET.

Donald Trump won the state in 2016 by a 5% margin, but Democrats are hoping it can be turned for Biden. We'll now have to wait a little longer to find out.

Donald Trump is projected to win his 10th state of the night - South Carolina. It's another southern Republican stronghold. It's voted for the Grand Old Party in every race in the last 40 years.

Here's our North America reporter Anthony Zurcher's analysis on this projection:

For a few moments in the final months of this campaign, Democrats entertained thoughts that South Carolina might be within reach for Joe Biden. It’s seen some of the demographic changes that have made Georgia and North Carolina more fertile ground for the party.

It turns out that was not the case. It appears safe to say this will not be a landslide election for Joe Biden, and South Carolina will remain firmly Republican for another four years.

Alright, let's zoom out of the state-level happenings now and take a look at the national picture.

(Again, with the caveat that exit polls are still taking place, so these numbers will keep fluctuating throughout the night as more results come in.)

So far, Biden's been doing far better with women than Trump, though the Democrat's lead is slim when it comes to male voters.

Biden has a lead among all non-white voters, and his biggest margin is with black Americans - Trump's only won 11% of African American voters to Biden's 87%.

Angelica Casas
Video journalist, BBC News

This presidential election could be the closest seen in Texas in a generation.

Voters are motivated - 9.7m Texans voted early, surpassing the state’s record-breaking turnout in 2016.

And as the state sees a second spike in coronavirus cases, it’s being considered a toss-up with the Republican Party losing support.

A toss-up is exactly what I found at this polling station in San Antonio, where voters I spoke to supported each candidate in equal numbers. This is why they voted:

Another projection now: Alabama. But this southern state has long been a safe bet for Republicans, so it doesn't tell us a huge amount more about the race to the White House.

Trump's party has won it in 11 of the last 12 presidential elections.

Anthony Zurcher
BBC North America reporter

As the minutes turn into hours on election night in the US, Joe Biden has posted early leads in several swing states that would help clear his path toward the White House.

Donald Trump needs both Ohio and North Carolina in his column for his electoral maths to work out, but Biden has modest leads in both states with more than half of all voters reported.

Democrats shouldn't count on those margins holding up, however. As predicted, the early and mail-in votes trended toward Biden, while the election-day results have favoured Trump.

As more and more of those in-person votes are counted, the president will slowly, inexorably claw his way back.

It's just a question of whether there are enough votes left to count.

Meanwhile, Trump leads in Virginia, but the count there always trends Republican early, until the heavily Democratic suburbs of Washington, DC, report their results.

Appearances can be deceiving.

Democrat Joe Biden is projected to win Colorado. It’s a swing state and key election battleground. It was won by Hillary Clinton in 2016, and twice by Barack Obama, after a period of nearly 40 years when it voted mostly Republican.

And a quick reminder of what we mean when we say projections. Ongoing ballot counts are being used to predict - or project - the winner of each state and the nationwide vote. A state will not be projected as being won by a candidate, however, until enough data has been collected to declare a clear winner. That includes months of polling, exit polls on the day and some of the actual votes counted.

This year the BBC gets its data from polling firm Edison Research who do the field work for the exit polls and work with US networks in the National Election Pool.

When will we know who’s won Wisconsin and why does it matter?

Wisconsin is one of the states in the industrial Midwest which shocked pollsters by voting for Donald Trump over Hillary Clinton in 2016.

The state’s 10 electoral votes helped get him to the 270 electoral college votes he needed to win the presidency.

It was tight - Trump won by just 0.7% - but the result represented a seven point swing from the pollsters’ predictions.

This time round, the polls have Mr Trump behind by a similar margin.

Polls closed a little over half an hour ago.

Democratic Governor Tony Evers has said he expects to know the results on election night, or by the day after at the latest, even though early ballots are not being counted until election day.

Donald Trump is projected to win North Dakota.

The state is a firm stronghold for Republicans. Since 1940, only one Democratic presidential candidate has won the state: Lyndon B Johnson.

Image source, Getty Images

Fox News is projecting that Democrat John Hickenlooper has unseated Republican incumbent Cory Gardner for US Senate.

The Colorado race marks the first flip of a Senate seat: Republican to Democrat.

Hickenlooper was Colorado's governor from 2011 to 2019, and mounted a brief bid for the 2020 Democratic presidential nomination.

This Senate race matters. Republicans hold a thin three-seat advantage in the chamber, and there are 35 seats up for election tonight. A win in Colorado brings the Democrats one step closer to flipping the Senate.

We have more about the key Senate races to watch.

Polls have closed in a number of important states. And in the last half an hour, Donald Trump has been projected to win in West Virginia, Arkansas and South Dakota in addition to those reported in the previous hour.

New York state and Connecticut are projected to go to Joe Biden.

Those states, plus the ones projected earlier in the night, are edging both candidates forwards towards the goal of 270 electoral college voters needed to win the White House.

Right now, Biden has 80 electoral votes. Trump is on 51.

But the night is just getting started.

Delaware has just elected the first openly transgender state senator in US history, according to CBS, the BBC's US broadcast partner, and AP.

Sarah McBride will also become the highest-ranking transgender elected official ever to serve in America.

McBride, who worked as an intern in the Obama administration, currently holds the seat representing Delaware's first district, a Democratic area.

She's been an outspoken advocate for LGBT rights, previously serving as the national press secretary of the Human Rights Campaign advocacy group.

According to the LGBTQ Victory Fund, there are four openly transgender people currently serving in state legislatures.

Fund president Annise Parker said McBride's victory "gives hope to countless trans people looking toward a brighter future".

"Her victory will inspire more trans people to follow in her footsteps and run for public office."

Earlier tonight we showed you pictures of pups at the polls, but cats also play a role in the US election process.

Ohio's Athens County Board of Elections Office has a beloved official mascot named Pumpkin. The cat hangs out in the window of the local election office year round, and is so well liked that members of the community pay her medical bills.

Pumpkin has previously been taken off-site during election time because she “gets nervous” during the chaos, elections director Debbie Quivey told the Athens Messenger, external.

What a scaredy cat!

Donald Trump is projected to have won in South Dakota.

Home to America’s iconic Mount Rushmore, the state has voted Republican in every election since 1968.

Joe Biden is projected to win in the state of Connecticut.

The Constitution State has voted Democrat in every race since 1992.

Image source, Reuters

With a rise in gun sales in the run-up to election day and concerns about the bitterly divided state the US finds itself in, there were fears of violence and disruption on Tuesday.

But there have been only a few reported incidents of run-ins at polling stations or in the streets.

In Chicago, a man told police that a group of people attacked his car with baseball bats near a polling station, reports the New York Times.

And in Charlotte, North Carolina, an armed man wearing a Trump hat was arrested after he reportedly intimidated people at a rally.

Overall, most Americans went out to vote peacefully - and of course many are staying at home after more than 100m cast their ballots early.

Disruptions to voting have also been relatively minimal. We reported earlier that the FBI is investigating a series of automated calls spreading misinformation. Dana Nessel, the MIchigan attorney-general, said she had received reports of robocalls to residents in Flint, which falsely claimed that people should vote tomorrow because of long queues.

Letitia James, the New York attorney-general, also announced an investigation into automatic calls in her state.