David M. Rubenstein is passionate about U.S. history and has given more than $75 million to local historic sites and landmarks in the past five years. (Sarah L. Voisin/The Washington Post)

For the second time in three days, Washington philanthropist David M. Rubenstein has made a multimillion-dollar donation to a historic national landmark.

The latest gift — $10 million to Thomas Jefferson’s Monticello plantation, near Charlottesville, Va. — was announced Friday night at a dinner there.

It comes on the heels of his $5.4 million donation to the U.S. Marine Corps War Memorial, unveiled Wednesday.

The Monticello gift is the second of a two-part, $20 million Rubenstein donation. The site got $10 million in 2013.

The money will go toward Monticello’s Mountaintop Project, a multiyear effort to make the 5,000-acre plantation look as it did in Jefferson’s day and tell the stories of the free and enslaved people who lived there.

Rubenstein, co-founder of the Carlyle Group, a Washington-based global private-equity firm, is passionate about U.S. history and has given more than $75 million to local historic sites and landmarks in the past five years.

Monticello, built between 1769 and 1809, was the elegant, neoclassical home of Jefferson, the chief author of the Declaration of Independence and third president of the United States. Its name means “little mountain” in old Italian.

Rubenstein said in an interview Tuesday that he had made a visit there about two years ago for the first time since he was a child. He said the site looked as though it needed some rehabilitation.

He said he told Leslie Greene Bowman, president of the foundation that runs Monticello: “I’m happy to help in some way. What would it take to fix it?”

“She said it will probably take about $20 million,” he said. “I said, ‘Okay, let me give you the first 10, see what progress you make, and then if it works out, I’ll give you another 10.’ ”

“They did a very good job on the first 10,” he said. “And now this is the second 10.”

In an interview Thursday, Bowman said, “I’m almost speechless with excitement.”

“We’ve been able to compress probably a decade of work into two or three years and peel back the layers of the 20th century to reveal the [plantation] as Jefferson would have known it,” she said.

The project, among other things, aims to bring back to life Monticello’s Mulberry Row, just south of the mansion, where many of its 130 slaves lived and worked.

“It was the main street of the plantation,” Bowman said. “It was not only slave cabins, it was workhouses and storehouses. . . . It’s literally like a little village, and it was lined with structures.”

The first part of the money went to get the landscape of Mulberry Row correct, she said. It also went to “re-create two slave structures, completely hand-hewn and handcrafted, the way they would have been and precisely on their archeological footprint,” she said.

The new donation will go, in part, toward restoring two original structures that remain along Mulberry Row from Jefferson’s time: a stone cottage that once housed weavers, and the mansion’s “south dependencies” wing.

The money will also help update some of the mansion’s famous first-floor rooms, such as the bedroom where Jefferson died July 4, 1826, at age 83.

“He had a way of locking his bedroom door with a long-distance chamber bolt, and we’re going to restore that,” Bowman said.

His gadget-filled “cabinet” room, where he spent hours every day writing and researching, also will get an upgrade and even more Jeffersonian gadgets.

“We now know a little bit more about those rooms, and how they looked,” Bowman said. “This gift is going to allow us to make some important changes.”