The Gulf Cartel is criminal syndicate based in Matamoros, Tamaulipas. Founded in the 1930's, it is amongst the oldest crime groups in the country. Originally focused on alcohol smuggling during Prohibition, it switched to other criminal activities after the 21st Amendment passed, and started selling cocaine from Colombia in 1984. This allowed it to grow, and would be the root of drug violence in Mexico as other drug trafficking organizations such as the Sinaloa Cartel and Juarez Cartel fought it for control of smuggling routes.