Souce

The race article from the Encyclopedia Britannica says that racial stereotyping started in the 18th century. It says that political leaders began to publicly assert that Africans were naturally inferior and were indeed best suited for slavery. Physical differences became the main basis to determine their social status. Racial Stereotypes were magnified by events such as the Haitian Rebellion of 1791, and other events. These events helped racial stereotyping continue to become more and more popular.