Legislation: Laws passed by Congress that make up part of the US policy. For example, the Homestead Act was a piece of legislation that influenced settlement in the western territories.
Executive Order: Directives issued by the President that have the force of law and impact US policy. An example is President Roosevelt's Executive Order 9066, which authorized internment camps during World War II.
Foreign Policy: The strategies and actions taken by the US government in its relations with other nations. It includes diplomacy, trade agreements, and military interventions.