After the takeover, anti-Batistas, liberals, urban workers, peasants, and idealists became the dominant followers of the M-26-7 movement, which gained control over Cuba. The Movement was joined with other bodies to form the United Party of the Cuban Socialist Revolution, which in turn became the Communist Party of Cuba in 1965. Cuba modeled itself after the Eastern European nations that made up the Warsaw Pact, becoming the first socialistic government in the Americas. Once it was learned that Cuba would adopt a strict Marxist–Leninist political and economic system, opposition was raised not only by dissident party members, but by the United States as well. Fidel Castro's government seized private land, nationalized hundreds of private companies—including several local subsidiaries of U.S. corporations—and taxed American products so heavily that U.S. exports were cut half in just two years. The Eisenhower Administration then imposed trade restrictions on everything except food and medical supplies. As a result, Cuba turned to the Soviet Union for trade instead. The US responded by cutting all diplomatic ties to Cuba, and have had a rocky relationship ever since. In April 1961, a CIA-trained force of Cuban exiles and dissidents launched the unsuccessful Bay of Pigs Invasion against Cuba, shortly after Castro had declared the revolution socialist. After the invasion, Castro formally proclaimed himself a communist.