Abraham Lincoln- preserved the union
Ronald Regan - trickledown economics
Theodore Roosevelt- built Panama Canal
George Washington - commanded continental army
Franklin D Roosevelt - new deal program
Thomas Jefferson - Louisiana Purchase
Andrew Jackson - expanded presidency
John Marshall - Marbury v Madison
a war between the allies (Russia, France, British Empire, Italy, United States, Japan, Rumania, Serbia, Belgium, Greece, Portugal, Montenegro) and the Central Powers (Germany, Austria-Hungary, Turkey, Bulgaria) from 1914 to 1918.
White House Chief of Staff
He commanded an attack where he committed mass genocide in 2001. this led to u.s. getting involved because they saw the rise of a modern day hittler.
I think that the best answer is the geographic location: many other countries (Sweden for example) have tried being neutral at different times but did not manage to: but the fact that the US has only two boundaries, and that both other countries also have a history of fighting from independence from a European power, makes it possible that unless US decideds to get involved in international politics, it can be "left alone".