District of Columbia v. Heller case only applied to federal gun restrictions in the city of Washington, D.C. It declined to rule on the question whether the 2nd Amendment’s protection of individual gun ownership applied also to state restrictions. The question would not have been controversial in the early republic, since many state constitutions—whether drafted before or after the U.S. Bill of Rights—had included a right to bear arms in their own Bills of Rights. As early as 1829, William Rawle wrote that if either a state or the federal legislature were to attempt a restriction on the people’s right to bear arms, the 2nd Amendment “may be appealed to as a restraint on both.” The applicability of the amendment to state legislatures, however, was by no means widely assumed in the 19th or 20th centuries, and the Court did not decide the question until McDonald v. City of Chicago in 2010.
Justice Samuel Alito delivered the opinion of the Court in McDonald. He explained that the governing question for determining if the 2nd Amendment should be incorporated into the Fourteenth Amendment was whether it was found to be “fundamental to the Nation’s scheme of ordered liberty” or “deeply rooted in this Nation’s history and tradition.” The majority of the Court decided, in another 5-4 decision, that both of these standards applied to an individual’s right to bear arms. In his dissent, Justice Stephen Breyer argued that he could “find nothing in the 2nd Amendment’s text, history, or underlying rationale that could warrant characterizing it as ‘fundamental’ insofar as it seeks to protect the keeping and bearing of arms for private self-defense purposes.”