Photo by Brian Allen.

A mansion located on the grounds of Arlington National Cemetery that was once home to Robert E. Lee will be restored with a $12.35 million gift from a local philanthropist.

The National Park Service says the donation from David M. Rubenstein will restore every room in the Arlington House to the 1860 condition. From a release:

An important aspect of this project is to restore the slave quarters to better represent and tell the stories of the enslaved. Visitors will learn from park rangers and volunteers, or via new mobile and web assets, in addition to audio tours and changing exhibitions. As visitors move between the mansion and the new museum and bookstore, they will pass along accessible paths that stretch through the restored grounds, including heirloom gardens and new trails. People who cannot visit in person will enjoy a more robust experience through virtual tours, complete with detailed displays of the rooms and museum objects.

The project will last about 30 months, according to the Post, and may require the closing of the museum and slave quarters for months. Arlington House, which overlooks the Potomac River, was originally built as a memorial to George Washington.

Rubenstein, co-CEO of the asset management company The Carlyle Group, has donated millions of dollars to various causes in D.C., including a $4.5 million donation to the National Zoo for a panda house, $50 million for the Kennedy Center and $7.5 million for Washington Monument repairs.