Musical theatre, as the United States’ only unique theatrical genre to find global influence, is a powerful form of storytelling that began as staged reifications of American ideals. The American musical has been a prime location to explore what it means to be American and how American society reckons with its self-proclaimed status as a “melting pot” where people from diverse cultures and ethnicities come together to form the rich fabric of the nation. Though much scholarship focuses on the American musical as a site to reify American culture and ideals, this dissertation critiques exclusionary American ideologies that have harmed disabled people, mad people, women, and people of color for as long as it has existed. In this project, I argue that passage of the Americans with Disabilities Act in 1990, which established legal protections for people with disabilities, made physical and mental disability visible and relevant to the narrative action and staging of musical theatre in new ways. Combining my professional skills as a dramaturg with theoretical frameworks from performance studies, disability studies, and women of color feminisms, I examine Violet (1997), Jane Eyre the Musical (2000), and Next to Normal (2009) as my prime case studies. Through analyzing these case studies, this dissertation reveals an obscured history of how racialized and gendered disability ideologies inflect the narrative and staging of American musical theatre. I term this aesthetic and practical reliance on mad characters mad dramaturgy.