There is evidence to support that the US was both internationalist in their action as well as wanting isolation. The demand of the country was to return to isolationism and 'return to normalcy'. However in a global market, economically the US could not isolate as our money was tied to the money of other nations. Therefore politically, the US could not completely step away either. Circular loans given to Germany to pay reparation brought the US closer to Europe economically. The Washington Conference was an international conference but the goal was to reduce arms to prevent future war and involvement. Additionally, the US refused to sign the Treaty of Versailles and did not join the League of Nations. Domestically, the country also instituted immigration restrictions in hopes of preventing world troublemakers from getting into the US.
By definition, the Columbian Exchange were the series of exchanges in different types of plant and animal species between the New and the Old World taking place in the Era of Exploration. Among the benefits that the Native Americans gained from the exchange was that European crops were introduced to the America.