During the union unrest in the US in the late 19th century, companies sometimes hired operatives and armed guards from the Pinkertons. In the aftermath of the Homestead Riot of 1892, several states passed so-called "anti-Pinkerton" laws restricting the importation of private security guards during union strikes. The federal Anti-Pinkerton Act of 1893 continues to prohibit an "individual employed by the Pinkerton Detective Agency, or similar organization" from being employed by "the Government of the United States or the government of the District of Columbia."