The change happened overnight into Wednesday.
It's the culmination of a months-long battle between the Trump administration and the City of Philadelphia.
The city fought to keep the slavery panels in place, saying that removing them violated an agreement between the federal government and the city.
Earlier this month, an appellate court ruled that the Trump administration did have the right to remove the panels.
This all started with an executive order from the president, seeking to remove content from national parks that he says inappropriately disparaged Americans past or present.