Stephen W. Kearny played a big role in the conquest and settlement of the West.
The career military officer captured New Mexico and established a government there during the Mexican-American War. He then moved his troops on to California in 1846 and was involved in some of the most important battles of the war. He became military governor of California in 1847.
Kearny died the next year of yellow fever—at the St. Louis home of his step-father-in-law William Clark, of Lewis and Clark fame.