The place of coinage is called the "mint." There are eleven mint service institutions in the United States, situated as follows: coinage mints at Philadelphia, San Francisco, and Denver; mints at New Orleans and Carson City conducted as assay offices; an assay office at New York, which has a large trade in bars of fine gold and silver; and assay offices at Seattle, Boise, Helena, Salt Lake City, and Deadwood, which also function as bullion-purchasing agencies for the large institutions.
The relative size and importance of the coinage mints are indicated by the following figures of the number (in millions) of pieces coined in the fiscal year 1918:
No gold was coined in the year 1918, the banner year of the mint, when, besides 714.1 million pieces for the domestic coinage, some 52 million pieces were made for the Philippine and foreign governments. The domestic coinage for 1917 was 406.5 million pieces, and for 1916 it was 155 million. The value of the coinage for 1918 was: silver, $35 million; nickel, $4.1 million; bronze, $4.4 million; total, $43.6 million. The seigniorage on the coinage for the year amounted to $13.2 million on the subsidiary silver, and $7.2 million on the minor coins - total, $20.5 million; this constituted a very large part of the total income realized by the Treasury from the mint service, which was $22.8 million. The operating expenses for the year were $2.2 million. To purchase metal for the manufacture of minor coins, Congress appropriates $200,000 as the minor coinage metal fund; there is an additional sum for the alloy metals.