Collection contains various items related to Pratt's missionary service and letters with his wives and other family. Includes a handwritten diary of Pratt and his wife, Phoebe Sopher Pratt, kept while the Pratts were on a mission for The Church of Jesus Christ of Latter-day Saints in South America from 1851 to 1852. Also included are three handwritten letters and eight fragments of manuscripts by Parley P. Pratt. All items date from 1851 to 1855.

Handwritten and signed letters mostly addressed to Martha D. Watt. Nine of the items are the originals while the remaining four are photostat copies. George Watt writes about family matters and relationships with his wifes, his activities in Salt Lake City, Utah, the Salt Lake Tribune newspaper, the Church of Zion, and his employment with Brigham Young, the second president of the Mormon Church.