Patentee or inventor searches only return results from 1920 to date on the uspto's advanced search screen. Do this without the double quotes: "in/your_inventor_here" ex: in/edison Even in the uspto's 1790 to present [entire database] the earliest Edison patent returned is from June 1920. The same search below will find 160 patents from 1876 to 1919. If you know a patent number you can look it up here.
On this site you can do a case insensitive search of references to pre 1920 patents.
It currently contains 357,078 unique patents (referenced by patents 1976 through 2019-12-31) which is about 27% of the utility patents issued before 1920. See
this page on where this data came from, including a Creative Commons Attribution acknowledgement.