Citing the evolving limits on the power of state and local government to tax, this article catalogues the major federal preemptions (more than half of which have been enacted since 1969) of state and local taxing powers, starting with those that relate to federal government instrumentalities and the treatment of federal employees (including service members) to that of interstate telecommunications and employment matters. It concludes by arguing that though a case can be made for selective federal preemptions of the state tax base there is an equally important concern that the federal government will overreach. By drawing on the work of the US Advisory Commission on Intergovernmental Relations, the article then offers a set of guidelines for avoiding what Alexander Hamilton would have likely regarded as a “usurpation of power not granted by the constitution.”