This paper argues that the use of masculine rhetoric in the expansion of the United States derived from a larger ideological system that glorified masculinity through imperialism. The United States relied on the frontier myth, a belief that asserted that the nation was formed through the struggle of settling the frontier. The American man possessed the strength to conquer the wilderness and the people who already inhabited it. This version of masculinity combined not only elements of nationalism but also of race. As the United States continued to expand its borders through imperialism, the masculine identity associated with the frontier myth persisted in the psyche of the American male. The conquering man became the ideal of the American man, and rhetoric regarding the national need for this figure in the continual expansion of America justified wars of imperialism. In order to observe recurring patterns of masculine rhetoric, this thesis adopts a comparative approach to American imperialism by analyzing two wars separated by time and political climate; the U.S.-Mexican War and the Spanish-American War. Systems of ideology are always embodied by people; consequently this thesis applies a biographical approach to the key political figures who influenced the United States’ route to war. These men serve as examples of the internalization and intersectionality of masculine rhetoric as well as the outward expression of those systems in the form of imperialism.