More than half of registered voters have already cast their ballots: Officials

While Election Day is finally here, more than 83 million people have already cast their ballots.

Election Day was trending on the busy side, with roughly half of the 161.42 million registered voters still heading to the polls.

In Georgia, one of seven key swing states, long lines were forming outside polling stations, officials said, despite more than 4 million people in the Peach State having already voted.

In Fulton County, Georgia's most populous county, which includes the city of Atlanta, nearly 30,000 people had cast their in-person ballots by 9:40 a.m. Tuesday, a little more than three-and-a-half hours after the polls opened at 7 a.m., said Nadine Williams, the Fulton County director of registration.

“All polling sites are secure with an active security presence," said Williams, adding that the county had received five "non-credible" bomb threats Tuesday morning, two of which prompted the evacuation of voting locations for about 30 minutes each.

"Outside of these brief interruptions, Election Day has been quiet, with minimal issues reported and we remain prepared to address any misinformation or additional disruption to ensure a smooth experience for all voters today," Williams said.

Of the 83 million voters nationwide who have already cast ballots, 45 million did so in person while 38 million mailed in ballots, according to the University of Florida Election Lab. About 37.7% of the early votes were cast by registered Democrats while 35.9% of Republicans voted early, according to the lab.

In the 2020 presidential election, 66% of eligible voters cast ballots, the highest of any national election. President Joe Biden beat Trump 51.31% to 46.85%, according to the Federal Election Commission.

This election is expected to be even closer than 2020.

An ABC News/Ipsos poll released Saturday showed Harris with an overall three-point advantage over Trump among likely voters nationwide, 49% to 46%.

Both Harris and Trump have spent the last week of the campaign barnstorming in battleground states, fighting tooth and nail for every last undecided vote. On Monday, the candidates engaged in a sprint to the finish line, holding multiple rallies in North Carolina and Pennsylvania.

In a sampling of nine states, including the battleground states of Georgia, Michigan, North Carolina and Pennsylvania, 54% of the early voters were women and 43.8% were men, according to the lab. The largest block of early voters, 39.4%, were 41- to-65-year-olds, while voters over 65 represented 34.5% of the early vote.

Younger voters -- 26 to 40 years old -- made up 17.5% of the early vote, while 8.7% of voters 18 to 25 cast early ballots, according to the lab.

Some states like North Carolina, another key swing state, have shattered records for early voting.

More than 4.4 million voters have cast early ballots in North Carolina, 4.2 million of them in person, according to the lab. The North Carolina Board of Elections said the number of early voters broke a record, surpassing the 3.6 million early votes cast in the 2020 election, officials said.

In the swing state of Pennsylvania, at least 1.8 million people voted early via mail-in ballots, according to the Florida Election Lab, which reported that 55.7% of the earlier voters were women and 32.8% were men.

Early voting in Georgia began on Oct. 15, and more than 3.7 million people voted in person, while another 265,648 cast mail-in ballots, according to the lab. A breakdown of the early voters showed 55.7% were women and 43.5% were men, according to the lab.

In other battleground states, Michigan saw 3.2 million voters casting mail-in ballots, 55% women and 44.9% men; 2.3 million cast early mail-in ballots in Arizona, 40.8% of whom are registered Republicans and 32% Democrats, according to the lab.

In Nevada, another swing state, a little over 1 million voters cast early ballots, including 543,271 who voted in person and 556,062 who sent in mail-in ballots, the lab reported. Of those who voted early in Nevada, 37.5% were Republican and 33.7% were Democrat, according to the lab.

And in the battleground state of Wisconsin, 1.5 million people voted early, including 949,157 who cast in-person ballots and 561,616 who cast mail-in ballots, the lab reported.

ABC News' Olivia Rubin contributed to this report.