President Biden will spend his final full day as president in Charleston, S.C., where five years ago he revived his flailing campaign and secured South Carolina’s crucial primary that was widely credited with putting him on the path to the White House.

Mr. Biden will start his day worshiping at the Royal Missionary Baptist Church, a historically Black congregation that he visited on the campaign trail in 2020 before clenching the endorsement of James E. Clyburn, the powerful South Carolina Democratic representative.

During Mr. Biden’s visit, he will observe Martin Luther King Jr. Day, according to a White House official, which will be observed nationally on Monday when Mr. Biden hands the reins of the country over to President-elect Donald J. Trump, who has often shown contempt for contemporary civil rights efforts. Following the service, Mr. Biden will deliver remarks at the International African American Museum.

Mr. Biden’s remarks will focus on Dr. King’s legacy and continued efforts to make his dream of a just society a reality, the White House official said.

It is Mr. Biden’s last official trip as president of the United States, an ode to a state — and its Black electorate — that he has repeatedly credited for enabling him to cap off a half-century career in politics with four years in the White House.

“The truth is I wouldn’t be here without the people of South Carolina,” Mr. Biden said during a January 2024 visit to the state, speaking to Black voters. “You are the reason that I’m president.”