after the cuban revolution of 1959 the castro government gradually expropriated all foreign-owned private companies, most of which were owned by american corporations and individuals. the immediate trigger was the refusal by american owned oil refineries to refine the crude received from the soviet union. faced with the prospect of no oil, cuba nationalized the three american refineries. this action escalated the us embargo on cuba, which responded by nationalizing all american owned property. eventually all cuban private property, largely owned by cubans sympathetic to the batista led dictatorship, was nationalized.