Dear Ms. Dahlin-Brown,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Plant Patent Case Files, 1930 - 12/26/1978 in the Records of the Patent and Trademark Office (Record Group 241 that may include the patents you seek. Please contact the National Archives at Kansas City (RM-KC) via email at firstname.lastname@example.org for access to these records.
Prior to 1930, the United States did not grant patents for plants. Records 1979 to the present are still in the custody of the United States Patent and Trademark Office (USPTO). Please see their guide to Patent Searching. For additional assistance, please contact the USPTO.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RM-KC. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!