Efforts like these were playing out in thousands of communities leading up to the voting on Tuesday — through a minority engagement program in Cleveland; a Latino civic group in Florida called Mi Familia Vota, which says it has registered some 30,000 new voters in the state; and a Values Bus Tour in California and Missouri sponsored by the conservative Christian Family Research Council.

Starting from the Cascade roller skating rink in Southwest Atlanta on Saturday, nearly 200 Care in Action canvassers fanned out across the city, armed with lists of voters who had not yet cast their ballots. Assata Aminifaa, 33, who worked cleaning buildings, caring for children and helping tend to her sick parents, has been with Care in Action full time since August, canvassing six days a week.

“I wanted to put my hands and my feet in, get busy being part of making history,” she said. Electing Ms. Abrams, she said, would show her 9-year-old daughter and 12-year-old son “there’s nothing you can’t do.”

She marched up to Keia Minor’s home and asked if she would vote on Tuesday. Ms. Minor replied that the only reason she hadn’t voted early for Ms. Abrams was that she wanted to bring her children along, the way her mother had shepherded her to the polls.

Her 18-year-old son would be voting for the first time, she said, and she made sure he understood how to read a ballot.

Ms. Aminifaa and a state senator who was accompanying her, Nikema Williams, encountered Rickie Thomas tinkering with a motorbike outside his house. He told them that when he tried to vote early, his local polling station was closed because of flooding, with no official notice posted about where else to go. But volunteers rushed to distribute fliers with alternate polling stations, so he was able to cast his vote for Ms. Abrams.

“I thought it was messed up,” he said. “We don’t fall for that thing that your vote doesn’t count.” He grew up in South Carolina and bears a scar on his stomach from falling after white children set a dog on him in elementary school, he said. “To think we’re going backward 30, 40 years,” he said. “That’s got to change.”