History of Mormonism, Sidney Rigdon was born in St. Clair Township, Allegheny County, Pennsylvania in February 19, 1793.
Born the youngest of four children, Sidney lived on a farm until 1818. He moved out and applied for a license to preach. He received his license and moved to Trumbull County, Ohio and preached with Adamson Bentley. He later married Bentley's sister, Phoebe Brook in June, 1820. Sidney became a pastor in a liberal Baptist church, many future Latter-day Saint leaders were part of Sidney's congregation, including Parley P. Pratt, Issac Morley, and Edward Partridge.
In 1830, Parley Pratt heard of the Book of Mormon and traveled to Palmyra to hear about it some more. He soon became converted and was called to serve a mission. On his mission, Parley stopped by Sidney's house and talked with him about the Book of Mormon. Parley left him a copy of the Book. Sidney read it and was converted to the church. He talked to his congregation about the Book of Mormon, and was able to convert hundreds of people to the Church. Joseph Smith would later have Sidney be a spokesman of the Church, due to his powerful attitude and preaching.
After moving back to Ohio, Joseph and Sidney received much persecution. A mob one night came, broke into Joseph's house, dragged him out, and tarred and feathered him. After tarring and feathering Joseph, they came to Sidney's house and tarred and feathered him to. When they dragged him out, Sidney's head bounced on the hard rocky ground, causing permanent damage. After the event, Sidney was never the same.
He served with Joseph through many hardships, including prison, the failing of the Kirkland Society Bank, and the constant moving because of persecutions
After Joseph was assassinated in June, 1844, Sidney told the Church that he was to be next in line to be prophet. After the saints received a revelation during Brigham Young's speech that he was to be the next ordained prophet, Sidney and some followers left the church and started their own, which became unsuccessful.
Sidney died in New York in 1876, still holding on to his testimony about the Book of Mormon and his belief that he was the next prophet.