<P> When it became known that the Denver Mint had struck only 2,630,030 nickels in 1950, the coins (catalogued as 1950 - D) began to be widely hoarded . Speculation in them increased in the early 1960s, but prices decreased sharply in 1964 . Because they were so widely pulled from circulation, the 1950 - D is readily available today . A number of reverse dies with an S mint mark, intended for the San Francisco Mint, were created in 1955; they were not used as that mint struck no nickels that year and subsequently closed, and the unused dies were sent for use at Denver, where the S mint mark was overpunched with a D. 1949 and 1954 are other years where one mintmark was punched over another . </P> <P> Proof coins, struck at Philadelphia, had been minted for sale to collectors in 1938 and continued through 1942 . In the latter year proofs were struck in both the regular and "war nickel" compositions, after which they were discontinued . Sales of proof coins began again in 1950 and continued until 1964, when their striking was discontinued during the coin shortage . In 1966 a small change was made to the design to add the initials of the designer (FS) to the obverse, underneath Jefferson's portrait . In commemoration of that change, two proof 1966 nickels with the initials were struck and presented to him . Special mint sets, of lower quality than proof coins, were struck from 1965 to 1967 . Proof coin sales resumed in 1968, with coins struck at the reopened San Francisco facility . Coins struck at any mint between 1965 and 1967 lack mint marks . Beginning in 1968, mint marks were again used, but were moved to the lower part of the obverse, to the right of Jefferson's bust . From 1971, no nickels were struck for circulation in San Francisco--the 1971 - S was the first nickel struck in proof only since 1878 . In both 1994 and 1997 matte proof nickels, with distinctive grainy surfaces, were struck in small numbers at the Philadelphia mint for inclusion in commemorative coin sets . </P> <P> During the late twentieth century the Mint repeatedly modified the design . In 1982, the steps were sharpened in that year's redesign . The 1987 modification saw the sharpening of Jefferson's hair and the details of Monticello--since 1987, well - struck nickels with six full steps on the reverse have been relatively common . In 1993, Jefferson's hair was again sharpened . </P> <P> In June 2002, Mint officials were interested in redesigning the nickel in honor of the upcoming bicentennial of the Lewis and Clark Expedition . They contacted the office of Representative Eric Cantor (Republican - Virginia). Cantor had concerns about moving Monticello, located in his home state, off the nickel, and sponsored legislation which would allow the Mint to strike different designs in 2003, 2004, and 2005, and again depict Monticello beginning in 2006 . The resultant act, the "American 5 - Cent Coin Design Continuity Act of 2003", was signed into law on April 23, 2003 . Under its terms, the Treasury Secretary could vary the nickel's designs in honor of the 200th anniversary of the Expedition and of the Louisiana Purchase, but the nickel would again feature Jefferson and Monticello beginning in 2006 . Under Cantor's legislation, every future five - cent coin will feature Jefferson and Monticello . </P>

When did they stop putting silver in nickles