In 1837 and 1838, he preached in New York City. Pratt later served as a missionary in the southern United States and in England, the Pacific islands, and South America. He moved to Chile to begin missionary work in Valparaíso. In 1852, Pratt and his family left Chile after the death of their child, Omner, without having had much success among the country's Catholic residents. In addition to having converted his brother Orson and preacher Sidney Rigdon, Parley Pratt introduced the Mormon faith to several future church leaders, including Frederick G. Williams, John Taylor and his wife, Leonora, Isaac Morley, and Joseph Fielding, along with his sisters, Mary and Mercy. Apostle In 1835, Pratt entered the leadership of the early Latter Day Saint movement when he was selected as one of the original Quorum of Twelve Apostles. While on a mission to the British Isles in 1839, Pratt edited the newly created periodical, Millennial Star. While presiding over the church's branches and interests in New England and the mid-Atlantic states, Pratt published a periodical entitled The Prophet from his headquarters in New York City. Missouri War After serving as a missionary in New York City, Pratt returned to church headquarters in Missouri in 1838. He was arrested in November 1838, along with Joseph Smith, and was held in prison in Richmond and then Columbia until escaping on July 4, 1839. His writings during this and other imprisonments with Smith comprise many first accounts and stories preserved about Smith. Writer Pratt was a noted religious writer and poet. Many of Pratt's writings are the only credible or lasting accounts from important American and Mormon events, such as the Hauns Mill Massacre and the events and conditions of imprisonment with Smith at Liberty Jail. Pratt's first printed work was "'The Mormons' So Called", a 5500-word account of the persecution of Mormons in Jackson County in 1833. Pratt wrote an autobiography, published after his death but likely his most widely read work in the 21st century. He published a book of poetry in 1835, the first collection of poems by a Latter-day Saint. Some of his poems have become staple Latter Day Saint hymns, some of which are included in the current hymnal of the Church of Jesus Christ of Latter-day Saints (LDS Church). Pratt wrote many of these hymns in 1839 while sailing to England to serve as a missionary. He was