Jonathan Morgan was born in Baltimore, MD, about 1777. In the application for a seamen's certificate below, Jonathan lives in Philadelphia, was born in Maryland, and the application is witnessed by his brother Thomas.
It can not be confirmed that the parents are as stated. More research needs to be done.
The National Archives and Records Administration; Washington, D.C.; Proofs of Citizenship Used to Apply for Seamen's Certificates for the Port of Philadelphia, Pennsylvania, 1792-1861. Source Information: Ancestry.com. U.S., Citizenship Affidavits of US-born Seamen at Select Ports, 1792-1869 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2010. Text: