Trump was introduced to the stage by Melania in an unannounced appearance.
The race for the White House remained essentially a dead heat on Sunday -- with nine days to go until Election Day.
Former President Donald Trump delivered a speech Sunday afternoon at New York's Madison Square Garden. After making several stops in Philadelphia on Sunday, Vice President Kamala Harris held a rally there Sunday afternoon.
Almost 42 million Americans have cast a vote through early voting methods, as of Sunday afternoon, according to data from the University of Florida's Election Lab.
The about 41.9 million recorded mail and early in-person votes were evenly split with about 21 million mail ballots returned nationally and about the same cast at in-person early voting polling sites across the country, the data showed.
Early voting options are now open to voters in 50 states and the District of Columbia. Many early voting periods will last until the weekend before Election Day.
Harris, taking reporter questions on Friday, was asked if she's cast her ballot yet.
Her running mate, Gov. Tim Walz, voted with his wife and son in Minnesota earlier this week.
Harris said she hasn't voted but "it's on my priority list for these next few days."
Trump is attempting to place doubt about voter rolls in Virginia after a judge ordered voters purged from election rolls as a result of Gov. Glenn Youngkin's directive to be reinstated.
A federal judge said on Friday Youngkin's program violated the National Voting Rights Act of 1993.
"This is a totally unacceptable travesty, and Governor Youngkin is absolutely right to appeal this ILLEGAL ORDER, and the U.S. Supreme Court will hopefully fix it! Only U.S. Citizens should be allowed to vote. Keep fighting, Glenn - AND REPUBLICANS IN VIRGINIA, KEEP VOTING EARLY!" Trump posted on his social media platform.
Republican National Committee co-chair Lara Trump is set to rally with Youngkin on Saturday. Trump said he plans to call into the rally to highlight the issue.
"I will be calling in to Glenn's Rally with Lara Trump tomorrow morning to talk about this crazy Ruling, and announce my final stop in Virginia before Election Day."
-ABC News' Lalee Ibssa, Soorin Kim and Kelsey Walsh
Pennsylvania's Lancaster County Board of Elections said that approximately 2,500 suspected fraudulent voter registration applications were dropped off at the election office in two batches around the deadline to register.
The deadline to register in the swing state was Oct. 21.
The board said "concerns were raised" during the normal review process and law enforcement was alerted.
Notably, the board says in its statement that the fraud was "identified and contained" and lauded this incident as one that shows that the election "system is secure."
"Our system worked," the board declared. "We will continue to operate with the highest levels of veracity, integrity, and transparency so that Lancaster County voters can be confident in our election."
-ABC News' Olivia Rubin
The Washington Post announced Friday it will not issue an endorsement in this year's election -- a first for the legacy newspaper in more than three decades.
"The Washington Post will not be making an endorsement of a presidential candidate in this election. Nor in any future presidential election. We are returning to our roots of not endorsing presidential candidates," publisher William Lewis wrote in a note explaining the decision.
The Post follows the Los Angeles Times in not backing a candidate.
Both newspapers had endorsed President Joe Biden in 2020 against Trump.
