Original: Joseph Smith, Jr. (December 23, 1805 - June 27, 1844) was the founder of the Latter Day Saint movement, also known as Mormonism, and an important religious and political figure during the 1830s and 1840s.
Simplified: Joseph Smith, Jr. (b. 23 December, 1805 - June 27, 1844) was the founder of Mormonism.