Throughout the 20th century, arguments over the meaning of the 2nd Amendment generated significantly more heat than light. To a great extent, this was because the Supreme Court never offered a definitive interpretation—instead, it dropped hints. In United States v. Miller (1939), the Court considered whether a criminal defendant had a 2nd Amendment right to possess a short-barreled shotgun despite a federal statute that outlawed possession of such weapons. The Court found no such right because the shotgun had no “reasonable relationship to the preservation or efficiency of a well regulated militia.” Thus the Miller Court seemed to be saying that the right to keep and bear arms was at least related to potential militia service—but the wording of the ruling left its implications unclear. Lacking any better guidance, many lower federal courts relied upon Miller to hold that the 2nd Amendment could only be invoked when the question involved maintaining a militia. Indeed, some courts decided that individuals did not possess any 2nd Amendment rights unless they were already enrolled in a state militia.