what is the twenty-cent piece?
A coin struck from 1875 to 1878
Twenty-cent piece (United States coin)
The American twenty-cent piece is a coin struck from 1875 to 1878, but only for collectors in the final two years. 
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Twenty-cent piece (United States coin) [SEP] Introduction
The American twenty-cent piece is a coin struck from 1875 to 1878, but only for collectors in the final two years. Proposed by Nevada Senator John P. Jones, it proved a failure due to confusion with the quarter, to which it was close in both size and value. In 1874, the newly elected Jones began pressing for a twenty-cent piece, which he stated would alleviate the shortage of small change in the Far West. The bill passed Congress, and Mint Director Henry Linderman ordered pattern coins struck. Linderman eventually decided on an obverse and reverse similar to that of other silver coins.