The National Park Foundation, the charity arm of the park service, bought the home from the King Center for $1.9 million. Money for the purchase came from private gifts by anonymous donors, and the home was turned over to the National Park Service on Nov. 27, Will Shafroth, the foundation president, said on Friday. News of the sale surfaced this week.

“We didn’t get to renovate it at the level that it should have been and preserve it at the level it should have been,” Bernice A. King, Dr. King’s daughter and chief executive of the King Center, said. “I think the time was ripe to do this, and it gives us an opportunity to transfer this to an entity that does an extremely good job at preserving and telling the stories of our history in America.”

The park service has been running tours of the home since 1984, after Congress made it part of a larger national historic site that includes the King Center complex, which is also where Dr. King is buried.

“This is a big deal, one of the most important acquisitions,” Mr. Shafroth said.

He said the park service plans to “improve and enhance” the home, which in 2017 had 584,435 visitors. Details of the improvements, which will include repairs not visible to visitors, such as the heating, are still being determined. Mr. Shafroth said repairs would cost in the millions of dollars but could not provide a specific figure.