Davis was born in Fairview, Kentucky, to a moderately prosperous farmer, the youngest of ten children. He grew up in Wilkinson County, Mississippi, and also lived in Louisiana. His eldest brother Joseph Emory Davis secured the younger Davis's appointment to the United States Military Academy. After graduating, Jefferson Davis served six years as a lieutenant in the United States Army. He fought in the Mexican–American War (1846–1848), as the colonel of a volunteer regiment. Before the American Civil War, he operated a large cotton plantation in Mississippi, which his brother Joseph gave him, and owned as many as 113 slaves. Although Davis argued against secession in 1858, he believed that states had an unquestionable right to leave the Union.