The National Park Service says the financier and philanthropist is donating $18.5 million to help restore the Lincoln Memorial.
The money will go to repairing damaged masonry, cleaning the memorial and conserving murals inside. Also on tap: a huge expansion of exhibit, education and research space and a new elevator to improve access, according to the agency.
The money will also pay for a special project to show visitors some of the graffiti left on the underpinnings of the monument.
"These improvements will hopefully enable more people to better understand and appreciate Abraham Lincoln's remarkable leadership during one of the most trying periods in American history," Rubenstein said in a statement released by the park service. "I am humbled to be a part of honoring this great man and preserving this iconic memorial for future generations."
The agency made the announcement Monday -- Presidents Day.
"This donation will not only safeguard one of our most visited and recognizable memorials, but will preserve Lincoln's legacy for future generations to appreciate," Interior Secretary Sally Jewell said.
The Lincoln Memorial is one of the most visited and most recognizable monuments in Washington. It features a 19-foot, 175-ton marble Lincoln
seated inside a massive edifice bearing inscriptions from his speeches.
Work began on the memorial in 1914, 49 years after Lincoln's assassination. It opened in 1922.
In 1963, the memorial was the site of the Rev. Martin Luther King Jr.'s famous "I Have a Dream" speech.
The upcoming work will likely be the most extensive renovation to the memorial since its opening, The Washington Post reported
Rubenstein, co-founder of the private equity firm the Carlyle Group, has carved out a philanthropic niche helping pay to safeguard and preserve national treasures. The Lincoln project is the fourth time he has donated to help renovate national landmarks.
In 2012, he gave $7.5 million to help restore the Washington Monument after an earthquake damaged it. He gave $12.35 million in 2014 to restore Arlington House, the memorial to Confederate Gen. Robert E. Lee. And in 2015, he gave $5.37 million to restore the U.S. Marine Corps War Memorial.
He's also purchased rare copies of documents with significant links to American history, including the Magna Carta
and a Puritan psalm book
He even donated $9 million to panda conservation efforts to help the National Zoo keep its popular pandas.
He told the CBS news program "60 Minutes" last year that part of the reason why he does what he does is because the government no longer has the resources.
"We have gigantic budget deficits and large debt," he told the show. "And I think private citizens now need to pitch in."