Silver and U.S. Coinage.

As early as 1652, Massachusetts had produced silver coins from its mint in Boston but in the early 1680s, British authorities pressured them to close down this important source for coinage. At about the same time (1804) as the increased half dollar coinage, Mint Director Elias Boudinot stopped the coinage of silver dollars. This was due to fewer of the Spanish 2-reales coins being imported from the West Indies and Mexico; however, in 1807 the tide turned and quarter dollar coinage was suspended until 1815. Coinage of Morgan dollars carried on at a strong pace since the government was forced to buy a considerable quantity of silver each month for coinage. [Extracted from the article]