...or in mathematics in the United States navy from 1833 to 1835. Engaged in surveying the Cherokee country in the winter of 1837-38, he began his famous explorations, first in the country between the Missouri River and the British possessions. He had been appointed second lieutenant of topographical engineers in July. In 1841 he married a daughter of Senator Thomas H. Benton, and in May, 1842, he bega...