There was no mistake. If you want to be technical, black refers to the Transatlantic slave trade which started around 1440–1500, and lasted until the 19th century. Black Americans have technically only been free of slavery for less than 200 years seeing how slavery ended in 1865. If you do the math the fight for equality passes 400 years. Are you going to nitpick every one of my comments in defense of a murderer? Because I’m not looking for commentary from racist Peter Liang sympathizers.