The earliest United States patents— sometimes called “name and date patents” because they were not numbered—are distinctive in many respects. Patent specifications were not required to include claims until the Patent Act of 1870. Moreover, while the 1790 Act required a substantive examination by a Patent Board, that requirement ended with the 1793 Act, when it was deemed too burdensome. Thereafter the evaluation of the sufficiency of patent specifications was left to the courts.
Berry, Robert H. "The X Patents: Patents Issued under the Patent Acts of 1790 & 1793." PTRC Innovations May 2015.