The term originated from the black civil rights. It was originally used by Marcus Garvey, then again by black mine workers in 1940, and was generally meant to being aware of social and structural chains binding black people from freedom and equality.

Leave it to US right-wingers to coopt a black rights term to mean something they hate.

Edit: I originally had "If I remember correctly," at the beginning, but then I remembered I had an archive spanning the majority of human history at my fingertips and just looked it the fuck up.