Answer
The Journal of Discourses (often abbreviated as J. D.) is a 26-volume record of public statements of the early leaders of the Church of Jesus Christ of Latter-day Saints (LDS), or Mormon Church. Many different kinds of speeches were printed, “including the prayer given at the laying of a cornerstone of the Salt Lake Temple, a report of a high council court decision, a funeral sermon, and a plea for the defendant and the charge to the jury in a murder trial. In all, the collected Journal of Discourses contains 1,438 speeches given by fifty-five people, including Presidents of the Church, members of the Quorum of the Twelve Apostles, members of the seventy, and sixteen other speakers. Brigham Young gave 390; John Taylor, 162; Orson Pratt, 127; Heber C. Kimball, 113; and George Q. Cannon, 111. Twenty-one people gave a single speech, and the rest gave from 2 to 66 speeches” (https://eom.byu.edu/index.php/Journal_of_Discourses, accessed 2/23/20).
The work was the idea of George D. Watt, a stenographer for Brigham Young, who originally transcribed sermons for the Deseret News, the Salt Lake City newspaper. Since there were LDS members who did not have access to the local newspaper, Watt produced the Journal of Discourses as a semi-monthly periodical, mailed to subscribers wherever they may have resided. The individual issues were collected over time and eventually became the 26-volume work with material covering the years 1854—1886.
As the statements of early leaders have come under scrutiny, LDS leaders seem to try to disassociate themselves from the work, while still publishing it. The official LDS website notes that the Journal of Discourses is not an official publication of the church: “The Journal of Discourses includes interesting and insightful teachings by early Church leaders; however, by itself it is not an authoritative source of Church doctrine.” (www.churchofjesuschrist.org/study/manual/gospel-topics/journal-of-discourses?lang=eng, accessed 2/23/21).
Likewise, current LDS statements suggest that some of the material in the Journal of Discourses may have been inaccurately recorded: “Questions have been raised about the accuracy of some transcriptions. Modern technology and processes were not available for verifying the accuracy of transcriptions, and some significant mistakes have been documented” (ibid.).
However, at the time of their recording, statements of LDS leaders were considered authoritative. Brigham Young, speaking of his own statements, said, “I say now, when they are copied and approved by me they are as good Scripture as is couched in this Bible, and if you want to read revelation read the sayings of him who knows the mind of God” (Journal of Discourses, Volume 13, p. 264, https://jod.mrm.org/13/261, accessed 2/23/21).
Although current LDS leaders may try to distance themselves from statements of leaders in the past, they run into a problem in that the early leaders often claimed to be speaking authoritatively on behalf of God. If their statements are unreliable, LDS doctrine that flows from them would also be suspect.
All agree that the Journal of Discourses is an important source of history for the early years of the LDS organization. It is available full-text online.