Philanthropist David Rubenstein, who has already donated tens of millions of dollars to refurbish the Washington Monument and other icons, is giving $18 million to fix up the Lincoln Memorial.

The National Park Service announced the gift Monday. The money will be used to fix the memorial's roof, clean Lincoln's statue, repair marble panels and improve accessibility by adding a second elevator.

The park service also plans to create 15,000 square feet of visitor space in the cavernous space below the memorial for education.

Rubenstein said his admiration for Lincoln drew him to this project.

"Lincoln deserves to have his memorial in tip-top shape,'' he said in a phone interview with the Associated Press.

The Lincoln Memorial draws more 7 million visitors annually and is the most-visited attraction on the National Mall.

Park Service Director John Jarvis said the memorial, dedicated in 1922, is structurally sound but does need some repair work.

"It's pretty stout, and I think really has held up quite well for a structure of its age,'' Jarvis said. "But you can't build a 100-year roof.''

The memorial is built on pilings, and the park service is going to explore ways for visitors to see the foundations that anchor the memorial to the bedrock. The unseen superstructure is marked with graffiti from the workers who built the memorial over a seven-year period, including caricatures of former President William Howard Taft and memorial architect Henry Bacon.

Rubenstein, a billionaire who founded The Carlyle Group investment firm in Washington, has given hundreds of millions to help historic and patriotic memorials and causes in D.C. (Click here for a list of some of Rubenstein's large D.C.-area gifts.)

He said he hopes his donations have spurred others to think about giving.

Will Shafroth, president of the National Park Foundation, believes it has. He notes that donations to the foundation have grown from about $25 million three years ago to an expected $100 million in this fiscal year. On Monday, the foundation announced that a $350 million, five-year capital fundraising campaign begun in October 2013 is about half way to reaching its goal.

"Due to things like Mr. Rubenstein's generous gifts, we've tapped into a real vein of interest ... in highlighting the importance of these national treasures,'' Shafroth said.

"It's terrific, it's just terrific," said John "Chip" Akridge, a local developer who himself has supported the restoration of the National Mall and joined Rubenstein on a tour of the memorial Monday. "We need more and more of this ... not everyone has to give $18 million; $18 times 300 million people goes a long way."

Rubenstein, a history buff, said he is particularly excited that his gift will provide the park service a better opportunity to tell Lincoln's story to visitors at the memorial, and generally increase awareness about his presidency.

"It will be good if people read more about Lincoln and what he did to keep the country together,'' he said.

Standing outside in a snowstorm as the gift was announced, Rubenstein spoke more about Lincoln. "He made certain that the scourage of slavery was ended when it was ended," Rubenstein said. "It's one of the great tragedies of our country that we lived through slavery for such a long period of time."

Rubenstein has told the New York Times that about $200 million of the $300 million he has given away was "patriotic giving." He's given at least $43 million to Park Service properties in the D.C. area.

Here are a few of his D.C.-area gifts:

2007:

Rubenstein buys a copy of the Magna Carta for $23 million and loans it to the National Archives.

2011:

Rubenstein gives $13.5 million to the National Archives for its visitor center and for a new gallery

Rubenstein gives the Smithsonian's National Zoo $4.5 million for its giant panda program - then gave another $4.5 million in 2015.

2012:

Rubenstein gave $7.5 million to help repair the Washington Monument after an earthquake

2013:

Rubenstein gives $10 million to Mount Vernon

Rubenstein gave $50 million to the Kennedy Center for a large addition, part of $75 million that Rubenstein has given to the center over the years

2014:

Rubenstein gives $12.35 million for Arlington House, the home of Confederate Gen. Robert E. Lee on the grounds of Arlington National Cemetery

2015:

Rubenstein gives more than $5 million to refurbish the U.S. Marine Corps War Memorial, known as the Iwo Jima sculpture.