Was the United States successful in early containment of communism?
Based on the early Cold War, Cold War Origins, Berlin & NATO, Korea War etc.

Yes, it was. In fact, the containment policy prevented communism from expanding from Eastern Europe to other nations in Western Europe, Southern Asia or the Americas.

Explanation:

Containment was the foreign policy strategy adopted by the United States after World War II, aimed at stopping the extension of the Soviet zone of influence beyond its limits reached in March 1947 and at countering the states likely to adopt communism.

Mostly, support to foreign states was through financial aid, notably with the Marshall Plan, but also military with the creation of the North Atlantic Treaty Organization (NATO). Containment was an important part of the Truman Doctrine, which aimed to actively intervene in support of foreign political regimes in order to fight communism.  

d. she conquered the black sea coast and parts of poland.