The governments of Cuba between independence from Spain and the Revolution have been regarded as client states of the United States. From 1902 to 1932 Cuban and United States law included the Platt Amendment, which guaranteed the US right to intervene in Cuba and placed restrictions on Cuban foreign relations. In 1934, Cuba and the United States signed the Treaty of Relations in which Cuba was obligated to give preferential treatment of its economy to the United States, in exchange the United States gave Cuba a guaranteed 22 percent share of the US sugar market that later was amended to a 49 percent share in 1949.