 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 regions. 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 . 
