In the early 1920s and 30s, the first purpose-built mosques were established in the United States and Japan. Despite being on the far sides of the planet in Detroit and Kobe, their foundation reflected the ability of South Asian Muslim "religious entrepreneurs" to operate on what was by the 1920s a truly global scale. In tracing the commonalities between this first institutional emergence of Islam in two new world regions, the lecture identifies the global processes of religious competition and exchange and the reasons why Indian Muslims emerged at the forefront of them.