American identity is just as evocative as it is evasive in American culture. It means something distinct to each American yet binds individuals together as a nation. Its potential to be abstract does not diminish its power as a reality of American life. The story of America is important to our survival as a nation, and calling on identity has incredible potential to compel citizens to action. In this thesis, I explore the development of American national identity both as it grew naturally and was intentionally crafted by political and cultural authorities. More broadly I consider how political and cultural authorities called upon identity in each era I explore, and how these articulations informed identity going forward. In the analytical framework as proposed by Abdelal, I consider the content of identity throughout the most formative eras of American history and the degree to which it was contested. I employ an organizing framework of analysis by considering five theories of identity, which each fluctuate in prominence in each era, and which exist in varying degrees of concert and competition. The five theories are as follows: liberalism, civic republicanism, ethnocentrism, incorporationism, and progressivism. The thesis concludes with a consideration of American identity in the 21st century and beyond.