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.
Country legend Willie Nelson took the stage at Harris' rally in Houston.
He played "Mammas Don't Let Your Babies Grow Up to Be Cowboys" and "On the Road Again."
Beyoncé is also expected to appear at the rally tonight in her hometown.
Republican vice presidential nominee Sen. JD Vance, speaking during a town hall with North Carolina voters on Friday, said U.S. adversaries don't fear Vice President Kamala Harris.
“Why do you have Russia invading Ukraine during Kamala Harris' watch and why do you have Iran and Hamas attacking Israel during Kamala Harris' watch?" Vance said at the town hall in Monroe, North Carolina, moderated by Republican National Committee Co-Chair Laura Trump. "And why do you have China saber rattling during Kamala Harris' watch? It's because who could possibly fear Kamala Harris? No one, right?"
Vance added, "This is a woman who is terrified of softball media interviews and we think that she's going to sit in a room with Vladimir Putin and Xi Jinping."
Vance said that when former President Donald Trump was in office, U.S. adversaries feared the former president.
"That fear kept a lot of aggression in check, and it kept a lot of wars that otherwise would have started from starting in the first place," Vance said.
-ABC News' Hannah Demissie
Robert F. Kennedy Jr. filed an emergency application with the U.S. Supreme Court Friday seeking an order that forces Michigan Secretary of State Jocelyn Benson to remove his name from the ballot.
The Michigan Supreme Court said RFK Jr. could not remove himself.
A response from the state is due Monday at 4 p.m.
-ABC News' Devin Dwyer
South Carolina Circuit Court Judge Daniel Coble ruled against the ACLU Friday in its request for a temporary restraining order to give some 1,900 teenagers the chance to register to vote after the state's registration deadline.
The ACLU of South Carolina sued the DMV and State Election Commission after the DMV failed to offer 17-year-olds obtaining a driver's license and who would turn 18 before Election Day the chance to register to vote at the DMV, a provision entitled by the Voting Rights Act.
Judge Coble wrote "relief sought by Plaintiff is too drastic" and, this near to Election Day, "would create disorder in the voting system," according to the ruling.
Coble denied the ACLU's motion but did not dismiss the case. A spokesman for the ACLU of South Carolina told ABC it has not made a decision on whether to appeal his ruling.
"We are still seeking permanent relief from the SCDMV’s unlawful exclusion of 17-year-olds from the National Voting Rights Act 'Motor Voter' provision," ACLU-SC spokesperson Paul Bowers said in a statement to ABC.
-ABC News' Christopher Boccia
