In the Enderton family tree it mentions "the John Enderton who served in the Philadelphia City Militia during the Revolution." Here are more details about that:

We find a John Enderton who, in the "Sixth Series of the Pennsylvania Archives," is listed among the Privates Substitutes Fourth Class of the Fifth Battalion Philadelphia City Militia which served during the Revolution. On a certificate dated 7 Sep 1779 of Captain George Forepaugh, his Company Commander, John Enderton is listed among members being drawn in the Fourth Class and being called into actual service and directed to get themselves in readiness to march in three days. John Enderton's name again appears on a General Return of the Fifth Battalion; at that time he was "with the enemy" -- apparently either a prisoner or a Tory.