Benoni Campbell and his wife Mary Leonard joined the Church of Jesus Christ of Latter-day Saints in the early 1830s. They lived in Steuben County, New York, less than 75 miles south of Palmyra, New York, where Joseph Smith lived and where the Book of Mormon was published. He was about 33 and she was about 31 years old when they joined the Church. His older brother Benajiah was the first to join in November of 1830, followed by his parents in 1832.
Benoni and Mary moved their family to Kirtland, Ohio by 1835, where he associated with the Prophet Joseph Smith and worked as a carpenter on the construction of the Kirtland Temple. By 1841 they had moved about 70 miles west of Kirtland (to Homer, Medina, Ohio) where they apparently stayed until 1845, when they moved to Nauvoo. The next spring (1846), the extended Campbell family left Nauvoo with the other Latter-day Saints and began their westward exodus.
The Campbells stopped along the Mormon Trail at Mount Pisgah, Iowa, where Benoni's brother, Joel, died. Benoni took responsibility for Joel's family. After a brief stay at Council Bluffs, the Campbells went to Holt County, Missouri to earn enough money for their journey to the Salt Lake Valley. It wasn't until 1850 that they resumed their trek. Along the way, both Benoni and Mary were stricken with cholera and died. They were buried along side the Mormon Trail. The rest of their family continued on to Utah.
PAF documentation notes and sources:
Benoni and Mary Campbell were baptized into the early Mormon Church in the 1830's when the church was in its infancy.
The first of the family to join the church was Benoni's brother Benajiah in November of 1830, a scant seven months after the church was founded at Fayette, Seneca County, New York. Benoni's parents were baptized in 1832, at the same time that Brigham Young was baptized. Benoni was also baptized in the 1830's and moved with his wife and their oldest children to join with the main body of the Saints in Kirtland, Ohio.