特許請求が初めてされたのはいつ？
The first Patent Act of the U.S. Congress was passed on April 10, 1790, titled "An Act to promote the progress of useful Arts". The first patent was granted on July 31, 1790 to Samuel Hopkins for a method of producing potash (potassium carbonate). A revised patent law was passed in 1793, and in 1836 a major revision to the patent law was passed. The 1836 law instituted a significantly more rigorous application process, including the establishment of an examination system. Between 1790 and 1836 about ten thousand patents were granted. By the Civil War about 80,000 patents had been granted.
method of producing potash (potassium carbonate)