us history unit 8 By reco 1945 22nd amendment 1945 united nation fromed 1947 truman doctrine 1948 marshall plan 1948 berlin airlift 1949 nato established 1950 korean war 1951 early cold war (1945-1960) 1952 first born detnonated by the usa 1955 jonas salk invents the polio vaccine 1957 ussr launches spunink 1962 cuban missile crisis 1964 the gulf of tonkin resolution 1965 medicare are medicaid ed established 1968 tet offensive 1969 tinker v. des moines 1971 pentagon papers leaked 1973 war powers act 1975 26th amendment 1975 fall of sagion, marks the end the Vietnam war