The election process is officially underway in many states across the country, but how voters are casting ballots differs by state. The first in person votes were cast Friday in three states. In Minnesota and South Dakota, absentee voters were able to head to the polls. In Virginia any registered voter can now cast a ballot. Several states have now sent absentee ballots to voters living overseas or serving in the military.

The first mail-in ballots will go out Saturday in Maryland and New Jersey.

"Vote early. Vote absentee. Vote on Election Day. Do whatever you want, but you have to vote," former President Donald Trump told rally-goers at an August rally in Atlanta.

With more options for voting than ever, presidential campaigns are treating every day like Election Day.

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"Your voice is your vote North Carolina. And you are going to make all the difference in the outcome of this race," Vice President Harris said at a Greensboro, North Carolina Rally on September 12.

The first major early voting practices date back to the Civil War. Many soldiers were fighting out of state but were allowed to cast votes as if they were present at the polls. By World War II, every state allowed soldiers to vote absentee.

"At the beginning of the 20th century, people started to realize we have a mobile population. We have people out on the railroads, building the railroads across the country, people who travel for business. And slowly, state by state, we introduced this option for people with a reason for voting by mail," said John Fortier, a senior fellow at the American Enterprise Institute.

Starting in the 1970s, some states began to offer mail-in voting for all registered voters, with no excuse required.

"In 1978, California was the first state to have no excuse absentee voting," Fortier said. "California and some other places started to think, well, let's make it more convenient."

Voters fill out their ballots at a polling station during Massachusetts state primary voting on Tuesday.

Voters fill out their ballots at a polling station during Massachusetts state primary voting on Tuesday.

Some states also began to allow limited in-person absentee voting. Texas and Tennessee were among the first.

By the 2000 election, 21 states allowed all registered voters to cast ballots by mail if they wished to do so. Arkansas joined Tennessee and Texas in allowing in-person early voting without an excuse. Every other state had a vote by mail option for absentee voters who provided an excuse as to why they could not make it to their polling location on election day. Yet, just 14% of ballots were cast early in 2000.

"Both of those trends [vote by mail and in person absentee early voting] have really stepped up and moved up really every year until they jumped up very dramatically again in 2020," Fortier said.

Amid the COVID-19 pandemic, the percent of early votes cast rose to 69%. Mississippi was the only state to require an excuse for voters to cast a ballot early. Texas and Tennessee, along with Louisiana and Indiana offered in-person early voting. Every other state allowed mail-in ballots.  Nine states and Washington, DC held all mail elections in which all registered voters were sent a ballot.

"2020 was an extraordinary year where we saw this huge jump up, even saw very different opinions of Democrats and Republicans about whether you should vote by mail," Fortier said.

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While the Trump Campaign has tried to make a push to get voters to cast ballots by mail, the former president has expressed criticism for all mail elections.

"You have to have an honest voting system because, you know, you don't have an honest voting system. They send out millions and millions of ballots. They go all over the place," former President Trump said in Rancho Palos Verdes, California on September 13. "Some people get 2, 3, 4 or 5. You have a very dishonest system over here. If I ran with an honest vote counter in California, I would win California."

Eight states and Washington, DC still have all-mail elections. New Jersey still permits the practice in small jurisdictions.

"There really is no one size fits all," Fortier said. "We have states like Oregon and Washington, who are basically 100% voting by mail. There are almost no polling places. We have some states in the northeast and some in the Deep South who really look much more traditional."

For the 2024 election, Alabama and New Hampshire have since shifted to the same strict requirements as Mississippi. Only absentee voters can vote by mail with a valid excuse like illness, living out of state or working a shift that conflicts with polling hours. Democrats have questioned efforts to limit access to voting.

Mail in ballots and former President Trump and Kamala Harris

(AP, left, AP/Jae C. Hong, top right, Sarah Rice for The Washington Post via Getty Images, bottom right)

"Across our nation, we are witnessing a full-on assault on other hard-fought, hard-won fundamental freedoms and rights like the freedom to vote," Vice President Harris said at a September 13 Wilkes-Barre, PA Rally.

Since 2020, seven other states have eliminated mail ballots for all voters, and now offer early in person voting instead. Overall, 36 continue to allow voters to cast ballots by mail.

"I personally think that there could be a value to having some early voting, but having four or 5 or 6 weeks of early voting is not necessarily better than having a couple of weeks of in-person early voting and really doesn't necessarily bring up turnout. And it's still really not any more convenient," Fortier said.

Pennsylvania was thought to begin sending out mail ballots on September 16th, but election officials clarified the timeline, saying they planned to begin processing ballots that day. They noted some delays due to Robert F. Kennedy Jr.’s request to be removed from the November ballot.

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"I do think people have a good instinct that they want there to be a ballot there, a tangible physical ballot. And we've moved in that direction with all of our voting technology to having ballots. But we also have very complicated ballots with many people on the ballot, sometimes ten, 20 races that you're voting for in a particular election. And that really does mean we need to use technology to count them," Fortier said.

The same legal fights have been happening in North Carolina.

"Unfortunately, all the ballots have been printed, but our Republican Supreme Court said, you've got to destroy all of those ballots and go back and print them again," North Carolina Governor Roy Cooper-D said after the presidential debate in Pennsylvania.

North Carolina is expected to send ballots to military and overseas voters on Friday. Federal law requires all ballots going overseas to be sent by September 21. All other North Carolina absentee ballots will go out next week. That’s almost three weeks after the state’s initial September 6 deadline for absentee ballots.

voting stickers

'I Voted' stickers sit on a table at a polling station in Massachusetts.

Some election officials have expressed concern over the mail ballot process and counting the votes, since some states have already sent ballots later than initially planned. One such state, Pennsylvania, will not start processing mail ballots until 7 a.m. on Election Day.

"States want to put in a lot of convenient parts of voting, and they don't necessarily think of how they all fit together. If you want to have early voting at many sites, you can vote anywhere, well you need a good database behind the scenes," Fortier said.

While 12 states, including swing state Arizona, will begin processing and counting ballots before election day, laws prevent those results from being reported until November 5th. 14 states including competitive Minnesota, will not begin tallying mail ballots until after polls close.  Toss-up state Nevada allows all mail elections. The state will still count ballots that arrive up to 4 days following election day, so long as they are postmarked November 5th.

"I'm an optimist and I think we'll probably see things be somewhat quicker than in 2020, which was such an extraordinary year," Fortier said. "Arizona has the most voting by mail of any of the states. Perhaps that will take a little longer, but I think there's a good chance that we'll be able to know the outcome unless it's very close."

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Our Fox News Poll from August showed Harris with a one point lead in Arizona. The Real Clear Politics  average shows Trump with just over a 1 point lead.

"The voting by mail is not going to be as high or as unexpected. And so, I think many states will be ready for that and be able to count more quickly," Fortier said. "If we're very, very close, we're likely to certainly see recounts. We're likely to see contests. And those things could take a very long time."