Production On August 12, 1974, the three designers were at the Philadelphia Mint, where they ceremonially operated the presses to strike the first coins bearing their designs. These prototypes were exhibited under armed guard at the American Numismatic Association convention in Florida the next day. They differ from all other Bicentennial coins in that they were struck in silver proof without mint mark; other silver proof coins bear an "S" mint mark as struck at the San Francisco Assay Office (as the San Francisco Mint was then known). Coins struck at Denver bear a "D" on the obverse; pieces lacking a mint mark were struck at Philadelphia. Sets of these prototypes were presented to President Gerald Ford, Counselor to the President Anne Armstrong and Director John Warner of the American Revolutionary Bicentennial Administration (the successor to the ARBC). All other first strikes were melted, with copies not even kept for the National Numismatic Collection. The Mint believed that if it was required to strike 1975 quarters, half dollars and dollars, not enough could be struck before it had to begin the Bicentennial issues to prevent the 1975 pieces from becoming collector's items. This risked coin shortages at a time when the Mint was seeking to build a surplus of quarters. Mint officials returned to Congress to seek amending legislation. President Ford signed a bill on December 26, 1974 that made several noncontroversial changes to law, including provisions to allow the Mint to keep striking 1974-dated pieces until it began striking the Bicentennial coins. By terms of the amending legislation, the commemorative coins could not be issued until after July 4, 1975. On November 15, 1974, the Mint began taking orders for the silver clad pieces, at a price of for proof sets and for uncirculated, with a deadline for orders of January 31, 1975. Uncirculated coins are like those newly released into circulation; proof coins have a mirror finish. Buyers were initially limited to five sets per person. On January 19, 1975, Brooks announced that the silver proof set price was cut to , and the order limit was waived. Buyers who had paid the higher price were sent refunds by check. Brooks stated that the price reduction was because of production efficiencies, the benefit of which she wished to pass along to the public. Numismatic columnist Ed Reiter noted, though, that the reduction came amidst protests from the numismatic