In the 19th century, still under Portuguese rule, Luanda experienced a major economic revolution. The slave trade was abolished in 1836, and in 1844, Angola's ports were opened to foreign shipping. By 1850, Luanda was one of the greatest and most developed Portuguese cities in the vast Portuguese Empire outside Continental Portugal, full of trading companies, exporting (together with Benguela) palm and peanut oil, wax, copal, timber, ivory, cotton, coffee, and cocoa, among many other products. Maize, tobacco, dried meat, and cassava flour are also produced locally. The Angolan bourgeoisie was born by this time.