You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
United_States_dollar

Context:
From 1792, when the Mint Act was passed, the dollar was defined as 371.25 grains (24.056 g) of silver. Many historians[who?] erroneously assume gold was standardized at a fixed rate in parity with silver; however, there is no evidence of Congress making this law. This has to do with Alexander Hamilton's suggestion to Congress of a fixed 15:1 ratio of silver to gold, respectively. The gold coins that were minted however, were not given any denomination whatsoever and traded for a market value relative to the Congressional standard of the silver dollar. 1834 saw a shift in the gold standard to 23.2 grains (1.50 g), followed by a slight adjustment to 23.22 grains (1.505 g) in 1837 (16:1 ratio).[citation needed]

Question:
How many grains of silver did the Mint Act define the dollar as?

371.25