“Developmentalism” is often regarded as the bête noire haunting liberal political theory, justifying modern civilizational hierarchies and liberal imperialism. But are all developmentalisms equally tied to Eurocentric, imperialist philosophies? I consider this question through a close reading of two of the most prominent, influential, and divisive modern accounts of historical development: those of Kant and J. S. Mill. I argue that Kant's philosophy of history is embedded in an Enlightenment idealism treating non-Europeans as bound to either adopt Western norms or fade into obscurity. Conversely, the influences of Romanticism and sociology led Mill to recognize cultural differences as indelibly affecting any society's development. Given this, I argue, against much of the current literature, (1) that Mill provides us with a significantly more capacious liberalism than Kant's; (2) that his developmentalism holds the conceptual resources to understand progress as a pluralistic and culturally differentiated process; and so, more broadly, (3) that not all liberal developmentalisms are equally bound to imperialist politics.