The polls will close over a seven-hour period on Tuesday, starting at 6 p.m. Eastern time in parts of Indiana and Kentucky and ending at 1 a.m. in western Alaska.
Here is a guide to when the first polls close in each state, and what races to watch at each point.
Show times in: Eastern Central Mountain Pacific Alaska HawaiiPolls open First polls closing First polls closed6 p.m. P.T.
Not all polls in each state close at the same time, and polls in some areas may close earlier than shown if all registered voters in that polling district have already voted.
There is also an unexpectedly competitive Senate race in Utah between Senator Mike Lee, a Republican, and Evan McMullin, an independent candidate.