portion of the District of Columbia that was ceded by Virginia in 1790 is re-ceded to Virginia. December 28, 1846 – Iowa is admitted as the 29th U.S. state. July 24, 1847 – After 17 months of travel, Brigham Young leads 148 Mormon pioneers into Salt Lake Valley, resulting in the establishment of Salt Lake City. May 29, 1848 – Wisconsin is admitted as the 30th U.S. state. 1848 – The Illinois and Michigan Canal is completed. March 3, 1849 – Minnesota becomes a United States territory Native Americans Chief Joseph of the Nez Perce was predicted to have been born in the 1840s Presidents The United States had five different Presidents during the decade. Only the 1880s would have as many. Martin Van Buren was president when the decade began, but was defeated by William Henry Harrison in the U.S. presidential election of 1840. Harrison's service was the shortest in history, starting with his inauguration on March 4, 1841, and ending when he died on April 4, 1841. Harrison's vice president, John Tyler, replaced him as President (the first such Presidential succession in U.S. history), and served out the rest of his term. Tyler spent much of his term in conflict with the Whig party. He ended his term having made an alliance with the Democrats, endorsing James K. Polk and signing the resolution to annex Texas into the United States. In the Presidential election of 1844, James K. Polk defeated Henry Clay. During his presidency, Polk oversaw the U.S. victory in the Mexican–American War and subsequent annexation of what is now the southwest United States. He also negotiated a split of the Oregon Territory with Great Britain. In the U.S. presidential election of 1848, Whig Zachary Taylor of Louisiana defeated Democrat Lewis Cass of Michigan. Taylor's term in office was cut short by his death in 1850. California In the first part of the 1840s, the modern state of California was part of a larger province of Mexico, called "Alta California". The region included all of the modern American states of California, Nevada and Utah, and parts of Arizona, Wyoming, Colorado and New Mexico. The United States, embarked on the Conquest of California in an early military campaign of the Mexican–American War in Alta California. The California Campaign was marked by a series of small battles throughout 1846 and early 1847. The Treaty of Cahuenga was signed on