Caroline Barnes Crosby was the sister to Louisa Barnes Pratt. She was born on January 5, 1807 in Warwick, Franklin County, Massachusetts, where she lived for three-and-a-half years before moving to East Canada. While there, her family joined the Church of England, and she also attended school during the winter months. After she was finished with school, she began teaching in the summer months, which she continued until her marriage. After this, she spent the winter months sewing with her sister, Louisa Pratt. She married her cousin, Jonathan Crosby, on October 26, 1832. The summer of 1834 was her last year of teaching, as she moved back to Massachusetts to live with her husband. Her husband had been a member of The Church of Jesus Christ of Latter-day Saints for a year previous to the marriage. Caroline was converted, and baptized into the Church January 18, 1835. The next fall, the Crosbys' moved to Ohio. While in Ohio, Caroline's husband, Jonathan, worked on the building of the Kirtland Temple. On December 14, 1836 Caroline gave birth to her only son Alma.

On January 3, 1838, Jonathan Crosby traveled in company with Brother Warren Smith to preach the gospel in Pennsylvania and Virginia. After this, he received a letter from his sister-in- law, Louisa Barnes Pratt, requesting he come and visit her and her husband, Addison Pratt. While there, he preached a sermon on the gospel, and after some debate and hesitation, both Louisa and Addison Pratt were baptized into the LDS church by Jonathan Crosby. In November of 1838, the Crosby family, along with the Pratt family, began to migrate west. They stopped at Pleasant Gardens, Indiana, where they lived for four year before their journey to Nauvoo on June 17, 1842. In the spring of 1848, they headed westward again and arrived in the Salt Lake Valley on October 12, 1848.

In April of 1850, both the Crosby and Pratt families were called to serve a mission to the South Sea Islands. Most of the journal entries found written by Caroline Barnes Crosby were written during this time. The families departed on May 7, 1850, and arrived to the islands on October 19. They enjoyed their time preaching the gospel on the islands, and on Monday, July 26, 1852 they set sail to return to their homes. They first lived in San Bernardino until January 1, 1858, when they set out for Salt Lake City. On October 19, 1858 they arrived in Beaver, where they remained for the rest of their lives. Caroline died on February 16, 1883.