After their releases (both were paroled), Lehder and Jung built up a small stream of money through simple, traditional drug smuggling - they enlisted two American girls to take a paid vacation to Antigua, receive cocaine, and carry it back with them to the US in their suitcases. Repeating this process several times, they soon had enough money for an airplane.
It was this rapidly growing network that became known as the Medellin Cartel. The partnership of Lehder and Jung handled transport and distribution, while Colombian drug lord Pablo Escobar handled production and supply. Other elements of the cartel, such as the Ochoa family, helped deal with political matters in Colombia. Ruthless violence was as integral to the process as cocaine itself.