Joseph Hooker was born in Hadley, Massachusetts, in 1814. He graduated from West Point in 1837 and entered the U.S. Regular Army as a lieutenant of artillery. He was an outstanding staff officer during the Mexican War, but, like so many other veterans of that conflict, he found peacetime advancement too slow, and he resigned his commission in 1853. The beginning of the Civil War found him in California, but he quickly made his way east and became a brigade commander under General McClellan.