As of Tuesday morning, more than 46 million Americans have cast their ballots in the 2024 election, representing over a quarter of the expected electorate, according to NBC News' tracker.

Both candidates, Vice President Kamala Harris and former President Donald Trump, have urged voters to go to the polls as quickly as possible.

With just a week until the Nov. 5 election, early voting is underway in all seven battleground states and dozens of others. Reports of hours-long lines at polling stations are already circulating on social media as voters flood the limited number of city spaces set up for early voting.

While millions of Americans lined up to vote in person, another 20 million cast their ballots by mail. According to the University of Florida's Election Lab, the 46.5 million early ballots are split almost evenly between ballots cast in person and by mail.

Some states, such as key presidential races North Carolina and Georgia, have reported that their early voter turnout is reaching records this election cycle.

In North Carolina, 353,166 ballots were accepted on the first day of early voting on Oct. 17, surpassing the record set on the first day of 2020, according to preliminary data from the State Board of Elections. More than 2.7 million votes had been cast nationwide as of Tuesday, according to NBC News.

Georgia also broke its first-day early voting record with an estimated 310,000 ballots cast on October 15. As of Tuesday, almost three million ballots had been received.

These historic voter numbers are testing the limits of America's early voting infrastructure, which operates with only a fraction of the workers and polling places that will be open on Election Day.

The goal of early voting is to give Americans more convenient alternatives to voting on Election Day. In some states, early voting also allows election officials to get a head start on processing or counting votes to spread the vote-counting workload over multiple days.

Elections and election laws are enacted by individual states, not the federal government. This creates a patchwork of elective surgeries across the country, each with their own rules.

Arizona, Michigan and Nevada, for example, are allowed to start counting their ballots before November 5th. However, in Georgia, Wisconsin and Pennsylvania, counting may not begin until Election Day.

According to the Associated Press, early votes accounted for about two-thirds of votes cast in the 2020 election.

This massive total of more than 100 million votes was largely due to the unique impact of the Covid-19 pandemic on American civic life.

While early voting data can provide helpful indications of early patterns within the electorate and voter enthusiasm, it is not a predictive measure of Election Day results.