In Dickerson v. New Banner Institute, Inc., 460 U.S. 103, 103 S.Ct. 986, 74 L.Ed.2d 845 (1983), the Court held that a State's expungement of a conviction did not nullify the conviction for purposes of the firearms disabilities Congress placed in 18 U.S.C. 922(g)(1) and (h)(1). In so ruling, the Court noted that our decision would ensure greater uniformity in federal sentences. See id., at 119-120, 103 S.Ct. 986. Provisions for expungement "varied widely from State to State," the Court observed, id., at 120, 103 S.Ct. 986, and yielded "nothing less than a national patchwork," id., at 122, 103 S.Ct. 986. The Court held that a state conviction was still a 'conviction' for 18 U.S.C. Sec. 922 purposes even though it had been expunged. 'Expunction does not alter the legality of the previous conviction and does not signify that the defendant was innocent of the crime to which he pleaded guilty.' Id. at 115. The Court further noted that presidential pardons do not exempt a conviction from Sec. 922, and that when Congress intended to completely discharge a person it knew how to do so. Congress . . . specifically provided in Sec. 844(b)(1) that such discharge or dismissal 'shall not be deemed a conviction for purposes of disqualifications or disabilities imposed by law upon conviction of crime . . . or for any other purpose.' This provision would be superfluous if Congress had believed that expunction automatically removes the disqualification. Congress obviously knew the plain meaning of the terms it employed in statutes of this kind, and when it wished to create an exception for an expunged conviction, it did so expressly. Id. at 118. The Supreme Court held that "whether one has been 'convicted' within the language of the gun control statutes is necessarily ... a question of federal, not state, law, despite the fact that the predicate offense and its punishment are defined by the law of the state." Id. 103 S.Ct. at 991. In Dickerson, the Treasury Department's Bureau of Alcohol, Tobacco and Firearms had revoked a firearm dealer's license because of firearms disabilities imposed under former 18 U.S.C. Secs. 922(g) and 922(h). The dealer's disability was his state felony conviction, which had been expunged by an Iowa court after he had successfully completed probation and before his license was revoked. The Supreme Court rejected the defendant's claim that he had not been convicted within the language of the firearms statutes. In addressing the question of whether the expungement pursuant to Iowa law "nullified his conviction for purposes of the federal statute," id. at 992, the Court stated that "for purposes of Iowa's own gun control statute, it might be argued that the conviction was nullified.... In any event, Iowa's law is not federal law, and it does not control our decision here. We therefore look to federal considerations in resolving the present case." Id. at 992 n. 9.