The United States was born in resistance to imperialism, but today comprises the most extensive empire in world history. With a particular emphasis on the post-1900 period, this course analyses the political, military, economic, and cultural developments that contributed to the transformation of this isolationist nation into the globe's dominant power. We will trace some of the winners and losers in this process, along with the resistance to American empire generated by opponents both within and beyond U.S. borders.