In general, English common law of the pre-constitutional period is one of the most important legal-historical sources of the meaning (and specifically the technical meaning) of many constitutional provisions. (footnote 1) English “common law throws light on the meaning and scope of the Constitution,” (footnote 2) because the common law is “is the system from which our judicial ideas and legal definitions are derived.” (footnote 3) “‘The interpretation of the Constitution . . . is necessarily influenced by the fact that its provisions are framed in the language of the English common law, and are to be read in the light of its history.” (footnote 4) Indeed:
The language of the Constitution cannot be interpreted safely except by references to the [English] common law . . . when the instrument was framed and adopted. The statesmen and lawyers . . . who submitted it to the ratification of the States, were born and brought up in the atmosphere of the [English] common law, and thought and spoke in its vocabulary . . . [W]hen they came to put their conclusions into the form of fundamental law in a compact draft, they expressed them in terms of the [English] common law, confident that they could be shortly and easily understood. (footnote 5)
Nonetheless, in determining what a provision of the Constitution means, WE THE PEOPLE “must look to those settled usages and modes of proceeding existing in the common . . . law of England before the emigration of our ancestors, which were shown not to have been unsuited to their civil and political condition by having been acted on by them after the settlement of this country.” (footnote 6) So, if there was “no settled practice under the English law,” that law “cannot . . . be treated as embedded in the [Constitution].” (footnote 7) And “every rule of the common law and every statute of England obtaining in the Colonies, in derogation of the principles on which the new government [of the United States] was founded, was abrogated.” (footnote 8) in such cases, not English common law, but “[o]ur own Constitution and form of government must be our only guide.” (footnote 9)
The admonition that “[o]ur own Constitution and form of government must be our only guide” applies to all other foreign law—which generally is completely irrelevant to, and totally excluded as an acceptable source for, interpretation and application of the Constitution.