Nicknamed "Old Rough and Ready," Zachary Taylor served more than 40 years as a professional soldier on the country's frontiers in Indiana, Louisiana, Minnesota, Wisconsin, Florida, and Texas. In the U.S.-Mexican War, he defeated the Mexican army in a decisive battle at Buena Vista and became a national hero. I lected president in 1848 by the Whig party, Taylor faced the most divisive political issue of the era: should the million square miles of new territories recently added to the country permit or prohibit slavery? Taylor was committed to preserving the Union with or without slavery. Lacking experience in political office, however, he refused to support a compromise proposed in Congress. Before the impasse was broken Taylor became ill and died in July 1850, after 16 months in office, leaving the dilemma to his suecessor, Millard Fillmore.