High Quality Content by WIKIPEDIA articles! Charles Proteus Steinmetz (April 9, 1865 – October 26, 1923) was a German-American mathematician and electrical engineer. He fostered the development of alternating current that made possible the expansion of the electric power industry in the United States, formulating mathematical theories for engineers. He made ground-breaking discoveries in the understanding of hysteresis that enabled engineers to design better electric motors for use in industry.