supposedly been destroyed to strike pieces for favored collectors or dealers. This practice led to incongruous pieces, with a dated obverse mated with a reverse not placed in use until years later. All pieces struck at the Philadelphia mint, without mintmark. See also Metric Act of 1866 References Explanatory notes Citations Bibliography Online External links Shield Nickels Website on Shield nickels, maintained by Howard Spindel, an authority on the nickel. 1866 introductions Five-cent coins of the United States