Richard Nixon
Nixon was very successful in diplomacy (relations negotiations with foreign countries). He began a policy called "détente" which reduced tensions between the United States and the Soviet Union. The two countries would get along and sign treaties that would limit the production of nuclear weapons between both sides.  Nixon traveled to communist China and established a very good relationship with them. Before that, there was almost no relationship between the United States and China. It opened up the door for decades of trade in the future, which is why many items in the United States were made in China.  His diplomacy with China is seen as one of his greatest accomplishments.  Later, under President Carter, the U.S. broke relations with the Republic of China and recognized communist China, not Taiwan, as the legal government of China.