 After returning from Mexico , Raynolds resumed mapping the U.S. – Canada border which he had been surveying before the war , then embarked on a project to develop water resources for the nation 's growing capital of Washington , D.C. Raynolds traveled the Great Lakes for several years surveying and mapping shorelines while identifying potential lighthouse locations . After promotion to first lieutenant and then captain , in 1857 he was assigned to design and supervise the construction of lighthouses along the Jersey Shore and the Delmarva Peninsula <unk> in the late 1850s Raynolds supervised construction of the Fenwick Island Light in Delaware and the Cape May Light in New Jersey . In 1859 , he made alterations to the Jupiter Inlet Light in Jupiter , Florida . 
