In recent years it has become fashionable to assail the “myth of statelessness”: the notion, promulgated by an earlier generation of historians that the American state was especially “weak” in this formative era. There is much to recommend these accounts. But there are also dangers in pushing this line of argument too far. In the late eighteenth and nineteenth-century United States, efforts to establish and enforce a uniform system of weights and measures--what one historian has described as a “constitutive element of state formation”--went nowhere. This troubled narrative calls into question the notion that the state was particularly powerful, effective, or pervasive in the early republic, never mind the longer nineteenth century. Much could get lost in translating the legal imperatives of the state into a practical reality, and the history of weights and measures in the United States offers an object lesson in how difficult it can be to make the one mirror the other. The American state could legislate, dictate, cajole, and threaten. But compared to more familiar forms of state power, from keeping the peace to collecting taxes, imposing standard weights and measures proved an extraordinarily vexing, perplexing challenge at this time.