50 State Quarters to form what is known as a "mule". Only sixteen of these specimens, produced on dollar planchets, escaped from the mint. A 2005 Minnesota double die quarter, as well as a 2005 Minnesota quarter with extra trees (another die error), have both triggered numismatic interest. An unusual die break on some 2005 Kansas quarters created a humpback bison. Relatively more common are Kansas quarters bearing the motto "IN GOD WE RUST." The United States produces proof coinage in circulating base metal and, since 1992, in separately sold sets with the dimes, quarters, and half-dollars in silver. For the silver issues,
U.S. state U.S. Constitution. Amendments may be proposed either by Congress with a two-thirds vote in both the House and the Senate, or by a convention of states called for by two-thirds of the state legislatures. To become part of the Constitution, an amendment must be ratified by either—as determined by Congress—the legislatures of three-quarters of the states or state ratifying conventions in three-quarters of the states. The vote in each state (to either ratify or reject a proposed amendment) carries equal weight, regardless of a state's population or length of time in the Union. Article IV also grants to Congress the