Mints
State quarters for circulation were struck in cupro-nickel by the Denver and Philadelphia mints (they carry the "D" and "P" mintmarks.) Proof copies in cupro-nickel and .900 fine silver were manufactured by the San Francisco mint. Issued in sets midyear throughout each year of the program, they carry an "S" mintmark and a frosted luster that distinguishes them from their circulating counterparts.
Designs
Each quarter depicts an historical event, emblem or landmark appropriate to the state it celebrates. New York has the Statue of Liberty, Connecticut the Charter Oak, while the New Jersey quarter has the crossing of the Delaware. The coins all share the Latin motto "E Pluribus Unum" ("out of many, one.")
Early State Quarters
The first state quarters to be introduced in 1999 were Connecticut, Delaware, Georgia, New Jersey and Pennsylvania, followed by Maryland, Massachusetts, New Hampshire, South Carolina and Virginia in 2000. As of 2010, well-preserved examples of the early circulating issues are becoming scarce and cupro-nickel proofs from the San Francisco mint fetch between $8 and $11.
Silver Proof Quarters
Silver proofs of state quarters were made in mintages of just under 900,000. As of 2010, they generally command a price of between five and ten dollars, but those from Kentucky, North Carolina, Rhode Island and Vermont are worth at least twice that. As they never served as currency, it is essential that they be in mint condition to retain their value.