Dear Mr. Kerber,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the Papers of the Continental Congress, 1774 - 1789 in the Records of the Continental and Confederation Congresses and the Constitutional Convention (Record Group 360) that contains some records related to letters of marque issued to American privateers. For more information about these records, please contact the National Archives at Washington, DC - Textual Reference (RDT1) at email@example.com.
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 RDT1. We apologize for this inconvenience and appreciate your understanding and patience.
Also, we searched online and located the following articles that may be of interest. The bibliography of the first may suggest further avenues for research.
We hope this is helpful. Best of luck with your research!