Congressional races, Senate races, gubernatorial races, it's all happening - we bring you the latest as the first polls close and the US decides its future.
All 435 seats in congress are up for re-election, with both houses of congress currently controlled by Republicans, if Democrats gain control of the House of Representatives (which they look poised to do) they could hamper President Donald Trump and the GOP's policies on things such as tax cuts and the Obamacare repeal.
In the Senate, 35 seats are up for grabs, most of them Democrats and it's very likely Republicans will keep control. Democrats will need to keep all their seats while gaining two from the Republicans to gain control.
If Democrats gain control of both houses, Trump's administration is in big trouble. All law-making and policy would be essential controlled by democrats, though Trump would retain a veto power.