The right to keep and bear arms was largely developed in English jurisprudence prior to the formation of the American Republic, thus predating the adoption of the U.S. Constitution. It was thus a part of the common law heritage of the original colonies. It is to this common law heritage that one must look to understand the right to keep and bear arms expressed in the Second Amendment. Sir William Blackstone, an authoritative interpreter of the common law and thus a strong influence on the framers of the Constitution, stated that individual citizens were entitled to exercise their "natural right of resistance and self- preservation, when the sanctions of society and laws are found insufficient to restrain the violence of oppression." Also, in his "Pleas of the Crown," Hawkins noted that "every private person seems to be authorized by the law to arm himself for various purposes." In sum, by the time of the American Revolution, English law had developed a tradition of keeping and bearing arms that extended back almost a millennium. The history of the Second Amendment indicates that its purpose was to secure to each individual the right to keep and bear arms, so as to protect individual rights and assist in the common defense. The framers did not intend to limit the right to keep and bear arms to members of a formal military body, but rather intended to ensure the continued existence of an unorganized armed citizenry prepared to assist in the common defense against a foreign invader or a domestic tyrant. In United States v. Miller, the only case in which the Supreme Court has had the opportunity to apply the second amendment to a Federal firearms statute, the Court avoided making an unconditional finding of the statute's constitutionality; it instead devised a test by which to measure the constitutionality of statutes relating to firearms.