This Article proposes a new account of how empire became constitutional. When the United States took a deliberate imperial turn in 1898—1899 by annexing Puerto Rico and the Philippines, many jurists thought that the Constitution automatically made these islands proto-states and their residents U.S. citizens with full constitutional protections. Three decades later, this expansive view was no longer mainstream. Contrary to standard accounts, this momentous change was neither quick nor the result of unilateral judicial action. To perceive dynamics extending beyond the judiciary, this study examines the attempts to win U.S. citizenship for Puerto Ricans by their first representative in Washington, Federico Degetau y González. Aware that constitutional meaning was not exclusively the province of courts, Degetau brought claims to U.S. citizenship before administrators, legislators, and the President as well. Officials responded with evasions through concessions. When Degetau sought a right as a citizen, they granted it on other grounds. Meanings of U.S. citizenship changed as officials reduced the rights that would accompany a grant of citizenship while envisioning without endorsing the possibility of noncitizen U.S. nationals. That novel idea—like the ideas of U.S. lands that would never be states and U.S. people with less than full constitutional rights—ripened into conventional wisdom and, eventually, similar doctrine that remains binding today. This suggests that the constitutional law of empire emerged as judges together with administrative and elected officials engaged in an iterative process in which they deployed forms of creative ambiguity to manage perceived conflicts between the Constitution and empire.