President Donald Trump has been moving to take greater control over the Smithsonian Institution and said earlier this week that the organization focuses too much on “how bad slavery was.”

Lindsey Halligan, the president's special assistant, told Fox News "we can’t just keep focusing on the negative."

President Trump has plunged once more into the nation’s cultural wars — this time with Washington’s famous Smithsonian Institution in his sights. As is often the case, the manner of Trump’s attack risks significant blowback,

President Donald Trump threatened to unleash his attorneys on the Smithsonian, saying the institution was fixated on “how bad slavery was.”

President Trump confirmed the White House is doing a review Smithsonian museums, where he complained "everything discussed is how horrible our Country is."

In April, the National Museum of African American History and Culture sparked controversy after it announced it would return several artifacts to their donors, including a Bible carried during a civil rights protest and Harriet Tubman’s book of hymns, NBC News reported.

Trump wrote: "The Smithsonian is OUT OF CONTROL, where everything discussed is how horrible our Country is, how bad Slavery was, and how unaccomplished the downtrodden have been — Nothing about Success, nothing about Brightness, nothing about the Future."

The White House is calling for a review of materials in the Smithsonian museums ahead of America’s 250th birthday next year.

Trump slams Smithsonian for focusing on slavery, sparks outrage over claims it ignores American success and "exceptionalism."

President Trump has ordered a sweeping review of the Smithsonian, saying it’s too “woke” and focuses too much on “how bad slavery was” instead of highlighting America’s progress and successes. NBC News’ Gabe Gutierrez reports.