This article seeks to explain the origins of the Dufoix law of 17 July 1984 which instituted a ten year residency permit for most foreign residents in France. It aims to clarify a series of debates about the relationship between the law and the March For Equality And Against Racism of 1983, by examining three mutually contradictory theories. The first theory holds that Mitterrand was persuaded to enact the reform as a direct result of his meeting with the Marchers on 3 December 1983. The second theory holds that the carte de 10 ans was a diversionary tactic, irrelevant to the Marchers and aiming to demobilize their movement. The third theory holds that the origins of the law lay less in the March than in earlier migrant worker movements of the 1970s. The article argues that the law ultimately resulted from a complex set of mutually entangled and ambivalent relationships.