The Helen Mar Whitney family papers represent a significant contribution to the study of early Latter-day Saints history, overland travel, Salt Lake City social history, and the development of the Arizona territory. The collection consists of over 100 letters dating from 1840 to 1900. Letters were penned from Nauvoo, Winter Quarters, the Mormon Trail, Salt Lake City, Mesa, Arizona, St. David, Arizona and other places. Diaries from family members chronicle the 1860s, 1880s, and 1890s. Due to Helen Mar Whitney's family ties, the authors of these documents were often members of the upper echelon of the LDS Church, thus making the collection's content even more significant. Her husband also associated with important members of the LDS Church and is reflected in his journals and correspondence.

The central figure in the collection is Helen Mar Whitney. Her correspondence begins with a letter written from Winter Quarters addressed to Horace at the "Pioneers Camp" on the Mormon Trail in June of 1847. Her last letters were received in the 1880s. The two largest sets of correspondence are with her husband Horace and her son Charles.

The letters to and from her husband mostly occurred between 1860-1861 and 1869-1870. The text is rich with information about events in Salt Lake City and the Utah area. The letters also allude to the relationship between Horace's plural wife, Mary Cravath, and Helen. Helen also carries on a lively correspondence with her youngest son Charles. Charles moved to the Arizona Territory in 1883 and stayed there through December of 1884. During this period, Helen and Charles exchange letters on almost a monthly basis.

Finally, Helen Mar kept a daily diary from 1885-1896. These diaries are rich with the social and political affairs that affected her life. While these diaries were transcribed and published by Charles M. Hatch and Todd M. Compton in 2003 as A Widow’s Tale: The 1884-1869 Diary of Helen Mar Kimball Whitney, Helen’s correspondence and the other family documents in this collection were not included in this publication.

In addition to the Helen Mar Whitney material, the collection also contains a significant number of letters and diaries from Charles S. Whitney. Charles' correspondence from his two-and-a-half years in Arizona is enlightening. He moved from Mesa to St. David and his work carried him throughout the territory. His letters describe haying, freighting and logging, as well as local Mexican celebrations and the local Indian populations.

Charles also kept a daily diary from 1881-1884. The diary began in Salt Lake City and continued through his stay in Arizona. Charles was 17 when he penned his first entry. He described his life in Salt Lake City in the early 1880s. Entries include work, home life, night life, and camping trips.

Of further importance are the letters and diaries of Horace K. Whitney. Horace wrote many letters to Helen. Two of these letters were written to her while he was traveling across the Mormon Trail in 1847. Horace also received one letter from his father, Newell K. Whitney, during this overland journey. He also corresponded with his son Charles when the young man was in Arizona. Finally, the collection has four journals kept by Horace K. Whitney. Two of these journals are photocopies and two are original. The earliest journal is a photocopy of an account book kept between 1850-1852. This volume recorded events in the LDS Church printing office, and with Horace's work with William Clayton in the tithing office from 1851-1852. The other photocopy is of a Horace K. Whitney notebook, 14.5 cm x 18 cm, that contains both a journal from 1869-1872 and financial entries from the same time.

Finally, there is a short diary of Horace's trip to southern Utah in the spring of 1863. This diary meshes with a group of letters that Horace sent to Helen while on the tour. The last item is a memorandum book covering the years 1860-1861.

The other significant material in the collection belongs to Orson F. Whitney. Two handwritten reminiscences about his life and a number of letters make up this material. In addition, letters written by Fanny Murray and Vilate Kimball in the 1840s are noteworthy.

This collection is unusual in that both outgoing and incoming correspondence exists, in original, for most of the Helen Mar Whitney letters. Because of the large block of letters to and from Helen it was decided to arrange this collection around her. These letters were arranged in alphabetical order for the outgoing material and in chronological order for the incoming. This arrangement was used for the Charles Whitney and Horace K. Whitney letters that did not involve Helen Mar, as well as the nonfamily correspondents.

Due to the size of some letters and their fragility, they have been encapsulated and placed into an oversized Box, Box 4. The items have been listed in the finding aid both in their appropriate place and in Box 4.