Peter Whitmer, Jr. (1809–1836) was the sixth child and fifth son of Peter Whitmer, Sr. and Mary Musselman. Born September 27, 1809 in Fayette, New York, Peter Whitmer, Jr. and several of his brothers became special witnesses of the Book of Mormon in June of 1829. Soon after joining the church on April 6, 1830, Whitmer was called to travel with Oliver Cowdery, Parley P. Pratt and Ziba Peterson on a special mission to preach Mormonism to the Native Americans. This mission led to the conversion of former Campbellite minister Sidney Rigdon.
Whitmer subsequently moved to Jackson County, Missouri, where he married Vashti Higley on October 14, 1832, with whom he had three children. By 1835, Whitmer and his family had relocated to Far West, Missouri, where he sat on the “High Council.” He died of tuberculosis on September 22, 1836 in Liberty, Missouri.
Source: www.MormonWiki.com (used by permission)