In 1782, Robert Morris, Superintendent of Finance, submitted to the Congress of the Confederation a plan for a national coinage and the foundation of an American mint, which met with endorsement. Jefferson suggested the decimal framework, with the dollar as the unit. Neither of these propositions was conveyed into effect until, in 1786, the Congress of the Confederation picked as the financial unit of the United States the dollar of 375.64 grains of pure silver, which unit had its starting point in the Spanish piaster or milled dollar, at that point the premise of the metallic circulation of the English settlements in America. This American dollar was never instituted, there not being at the time a mint in the young nation.
Congress passed the Coinage Act, establishing the first national mint in the United States, in 1792. Congress chose Philadelphia as the site of the first Mint. President George Washington appointed a leading scientist, David Rittenhouse, as the first director. Rittenhouse bought two lots at 7th and Arch Streets to build a three-story facility, the tallest building in Philadelphia at the time. It was the first federal building erected under the Constitution.
The Act of April 2, 1792 also built up the primary monetary system of the United States. The bases of the framework were: The gold dollar, containing 24.75 grains of fine gold, and stamped in pieces of $10, $5, and $2.50, designated separately eagles, half-eagles, and quarter-eagles; the silver dollar, containing 371.25 grains of unadulterated silver. A mint was built up. The coinage was boundless, and there was no mint charge. The proportion of gold to silver in coinage was 1:15. Both gold and silver were deemed legal tender. The standard was double. The Act of 1792 underestimated gold, which was along these lines traded. The Act of June 28, 1834, was passed to cure this by changing the mint proportion between the metals to 1:16.002. The last demonstration settled the heaviness of the gold dollar at 25.8 grains, yet brought down the fineness from 0.916⅔ to 0.899225. The fine weight of the gold dollar was hence decreased to 23.2 grains.
The Act of 1834 underestimated silver as that of 1792 had underestimated gold, and silver was pulled in to Europe by the more great proportion of 1:15½. The Act of January 18, 1837, was passed to make the fineness of the gold and silver coins uniform. The weight of the gold dollar was settled at 25.8 grains, and its fine weight at 23.22 grains. The fineness was subsequently changed by this demonstration to 0.900 and the proportion to 1:15.988+. Silver kept on being sent out. The Act of February 21, 1853, decreased the heaviness of the silver coins of a division under $1, which the Acts of 1792, 1834, and 1837 had made precisely corresponding to the heaviness of the silver dollar, and gave that they ought to be lawful tender to the measure of just $5. Under the Acts of 1792, 1834, and 1837 they had been full legal tender. By the Act of 1853, the lawful weight of the half dollar was lessened to 192 grains, and different divisions of the dollar in extent. The coinage of the fractional parts of the dollar was reserved to the government.
Boyd, James P. Triumphs and Wonders of the 19th Century: The True Mirror of a Phenomenal Era. 1899.