When is a dollar worth ten million dollars?

Beginning in the 1780s, a large number of prominent Americans called for the establishment of a central mint to supply the United States with official coinage; all such proposals failed due in large part to lack of funds and opposition from individuals and groups who preferred that coins be struck by the individual states. Since there were no federal coins issued, the needs of the states were fulfilled by a variety of domestic and foreign coins and tokens, including Spanish eight-real coins (popularly known as Spanish dollars or pieces of eight)

In 1789, the United States Constitution, which granted Congress the power "to coin Money, regulate the Value thereof, and of foreign Coin, and fix the Standard of Weights and Measures",

In 1791, following a study by Alexander Hamilton, Congress passed a joint resolution calling for the establishment of a national mint. Later that year, in his third State of the Union address, President George Washington urged Congress to provide for a mint, which was officially authorized by the Coinage Act of 1792. Despite the authorization, silver and gold coins were not struck until 1794. The Flowing Hair dollar, designed by Robert Scot, was initially produced in 1794, and again in 1795. In October 1795 the design was replaced by the Draped Bust dollar.was ratified and came into force.

The following year, Congress began deliberating on the state of the nation's monetary system and coinage. On January 28, 1791, Treasury Secretary Alexander Hamilton presented a report to Congress detailing the findings of a study he had conducted on the monetary system and the potential of a United States mint. As part of his study, Hamilton had a series of assay tests of Spanish dollars performed, as that was the coin upon which the United States monetary system would be based.

After viewing the results, the secretary recommended that the silver content of the United States dollar be based on the average silver content of the reales tested. Hamilton's recommendation was that the dollar should contain 371.25 grains of silver and have a gross weight of 416 grains, the balance being copper. On March 3, 1791, after reviewing Hamilton's report, Congress passed a joint resolution authorizing a federal mint; the resolution, however, gave no specifics or appropriations. 

The Flowing Hair dollar was the first dollar coin issued by the United States federal government. The coin was minted in 1794 and 1795; its size and weight were based on the Spanish dollar, which was popular in trade throughout the Americas,  On January 24, 2013, a specimen striking from the 1794 production sold for $10,016,875, the highest price ever paid for a coin.