All of U.S. history constitutes approximately 250 years, and during that period there have been many shifts in US domestic and foreign policy.
During the US Civil War, the anti-slavery goals of the North were shared by many abolitionist movements across the world. Although the Confederacy sought support from trading partners, the foreign policy of the north succeeded in keeping Britain and Europe neutral in the war. Thus US foreign policy of this period strongly focused on establishing the independence, sovereignty, and integrity of the US.
Much of the foreign policy of the United States in the nineteenth century had to do with the domestic issue of westward expansion, of creating a nation that controlled territory from the Atlantic to the Pacific ocean. The Louisiana Purchase, Mexican-American war, and War of 1812 all were part of this territorial policy.
The notion of "Manifest Destiny," partially enshrined in the Monroe Doctrine, was a foreign policy based on a growing sense of national identity rooted in a belief in the moral superiority of the United States and its political system. In domestic policy, this led to the Homestead Acts and other policies intended to encourage pioneers to settle the Midwest and West; in foreign policy it led to efforts to discourage European interference in the New World.
During the twentieth century, reactions towards communism were an issue of both domestic and foreign policy. The labor movement in the United States had strong links to global Marxism. The anti-communist purges and blacklists of the McCarthy era were closely connected to the Cold War and anti-communist foreign policies.