Alexander William Doniphan was a 19th-century American attorney, soldier and politician from Missouri who is best known today as the man who prevented the summary execution of Joseph Smith, founder of the Church of Jesus Christ of Latter Day Saints, at the close of the 1838 Mormon War in that state. He also achieved renown as a leader of American troops during the Mexican–American War, as the author of a legal code that still forms the basis of New Mexico's Bill of Rights, and as a successful defense attorney in the Missouri towns of Liberty, Richmond and Independence.

Joseph Smith Jr. was an American religious leader and the founder of Mormonism and the Latter Day Saint movement. Publishing the Book of Mormon at the age of 24, Smith attracted tens of thousands of followers by the time of his death fourteen years later. The religion he founded is followed to the present day by millions of global adherents and several churches, the largest of which is the Church of Jesus Christ of Latter-day Saints.