The former president was scheduled to speak at a Lancaster, Pennsylvania, rally later in the day before attending the New York Jets-Pittsburgh Steelers NFL game Sunday night.
Harris spoke at services at two congregations in battleground Georgia on Sunday morning as her campaign continues to encourage groups that are traditional Democratic voters to get to the polls.
"We all know your parents, who gave so much and led such an honorable life, and including, of course, among the leaders upon whose broad shoulders we stand, Congressman John Lewis, they they all knew, and by their example, they taught us that faith and good works go hand in hand, and that is especially true when it comes to protecting our sacred right to vote and getting souls to the polls," Harris said at Divine Faith Ministries International in Jonesboro near Atlanta.
Harris, who celebrated her 60th birthday on Sunday, was treated to a rendition of "Happy Birthday" by Stevie Wonder, who attended the Jonesboro service.
"People talk about a bucket list -- I think I have just checked off a whole big one to have Stevie Wonder himself sing me 'Happy Birthday,'" the vice president said.The vice president also taped an interview with MSNBC's Al Sharpton that will air later Sunday.
Harris' running mate, Minnesota Gov. Tim Walz, also tried to get out the vote at a church service and union hall in Michigan, another battleground state. He was to finish the day with fundraising events in Boston and Connecticut.
Trump's running mate, Ohio Sen. JD Vance, also met voters where they were, speaking at a bar near Lambeau Field, home of the NFL's Green Bay Packers, and at a tailgate party outside the stadium. He was to address a rally later in Wisconsin later in the day.
Trump has long challenged Harris' telling of life lessons she learned while working at a McDonald's during summer break while she was a student at Howard University. On Sunday, the former president took his trolling a step further by putting an apron over his shirt and tie and learning how to work the fryer.
During an impromptu news conference through the drive-through window where he was handing out orders, Trump repeated that he would accept the results of the election with conditions.
"Yeah, sure, if it's a fair election. Always. I'll always accept it if it's a fair election," Trump said, again questioning the integrity of the election system a little more than two weeks ahead of Election Day.
He also shot back at a reporter who asked how he would respond to sentiments that Harris is a more unifying candidate, saying he thinks Harris is "the most divisive person I've ever seen," accusing her of lying about her job applications.
Trump did wish Harris a happy birthday through the drive-through window, quipping that "maybe" he would give her flowers or some fries.
Senior Harris campaign adviser Ian Sams said Trump's McDonald's event was a sign of his desperation as Election Day nears.
"When Trump feels desperate, all he knows how to do is lie. He can't understand what it's like to have a summer job because he was handed millions on a silver platter, only to blow it," Sams said in a statement.
Harris has on a number of occasions talked about her experience working at McDonald's.
"Part of the reason I even talk about having worked at McDonald's is because there are people who work at McDonald's in our country who are trying to raise a family," she told MSNBC's Stephanie Ruhle in September.
Earlier, Trump defended his "enemy from within" comments to Fox News' Howard Kurtz and identified California Democratic Rep. Adam Schiff, who led impeachment efforts against him, and former House Speaker Nancy Pelosi.
"That's an enemy from within. That's really that is a threat to democracy. These are bad people. We have a lot of bad people, but when you look at Shifty Schiff and some of the others, yeah, they are, to me, the enemy from within," he said. "I think Nancy Pelosi is an enemy from within."
But he did say that he would not seek retribution against his opponents, even though he has said in the past that he would.
"No, I don't want to do that because that's a bad thing for the country. I don't want to do that. I don't know who said, I haven't said that I would, but they have done it," Trump said, referring to his opponents.