Originalists\u27 emphasis upon William Blackstone\u27s Commentaries on the Laws of England tends to suggest that the common law of the Founding era consisted in a set of determinate rules that can be mined for the purposes of constitutional interpretation. This Article argues instead that disparate strands of the common law, some emanating from the colonies and others from England, some more archaic and others more innovative, co-existed at the time of the Founding. Furthermore, jurists and politicians of the Founding generation were not unaware that the common law constituted a disunified field; indeed, the jurisprudence of the common law suggested a conception of its identity as much more flexible and susceptible to change than original...