Upon his return to the United States he was promoted to Rear Admiral and next became President of the Advisory Board, which position he gave up in 1885 for that of President of the Board of Inspection.
Simpson was regarded as an authority on all matters pertaining to ordnance and was the author of three books on the subject now used as teaxtbooks at the Naval Academy.
Throughout his career he acted in an advisory capacity on issues relating to ordnance, and one of his last offices was that of member of advisory boards whch designed the cruisers Boston, Chicago and Atlanta.
At the time of Simpsin's retirement, he had served 46 years in the U.S. Navy. In 1920, the Navy commissioned the destroyer USS Simpson in honor of his service to his country.
--Old B-Runner