President Trump issued an executive order this week criticizing the Smithsonian Institution for peddling what he described as a “divisive, race-centered ideology,” and calling to restore it to “its rightful place as a symbol of inspiration and American greatness.”

Here’s what to know about the Smithsonian, a sprawling network of federal museums that has been likened to America’s attic, and about the president’s order.

What is the Smithsonian Institution?

The Smithsonian Institution was established in 1846, with funds bequeathed by James Smithson, a British scientist, for the creation in Washington of “an establishment for the increase and diffusion of knowledge.”

Today, it includes 21 museums, libraries, research centers and the National Zoo, many of them on the National Mall in Washington. They range from behemoths like the National Museum of Natural History and the National Air and Space Museum to small institutions like the Anacostia Community Museum, in the southeast part of the city.

All Smithsonian museum sites are free. Last year, they collectively drew nearly 17 million visitors.

What has President Trump said about the Smithsonian?

In his executive order, Mr. Trump claimed that the Smithsonian had in recent years “come under the influence of a divisive, race-centered ideology,” and that it promotes “narratives that portray American and Western values as inherently harmful and oppressive.”

Mr. Trump directed that Vice President JD Vance work with Congress to prohibit expenditures on exhibitions or programs that “degrade shared American values, divide Americans based on race or promote programs or ideologies inconsistent with federal law.”