Americans are heading to the polls to choose a new president after one of the most rancorous election campaigns the country has seen.
Voting gets under way in earnest on the East Coast from 06:00 EST (11:00 GMT), though some villages in New Hampshire have already polled.
Hillary Clinton and Donald Trump criss-crossed America in a hectic last-minute campaign push for votes.
Results should begin emerging late on Tuesday night, US time, from 04:00 GMT.
Both candidates have held rallies in the battleground states of North Carolina, Pennsylvania and Michigan.