Photocopy of a handwritten diary by Henderson, documenting the years 1885 to 1887 when he served as a missionary in the British Isles for The Church of Jesus Christ of Latter-day Saints. He describes his journey from Utah to Liverpool with brother-in-law Anton Anderson, and he details his travels and ministry in Scotland, where he spent the entirety of his mission. Most of Henderson's religious, family, social, and tourist experiences as a missionary take place primarily in the southern part of the country in and around Glasgow and Edinburgh, but also in the northern region in Dundee and Aberdeen. Mission companions mentioned by Elder Henderson include: Elder Martin, Elder Ritchie, Elder Galt, Elder Lowe, and Elder Anderson. He also mentions associating with Elder B. H. Roberts in the summer of 1887.

Noteworthy transcriptions of documents and events contained in this diary include a blessing from Franklin D. Richards that set apart Henderson as a Mormon missionary, a letter Henderson writes to Apostle George Teasdale intended for inclusion in the Millennial Star, and a letter of appointment from George Teasdale requesting that Henderson preside over the Glasgow Conference in 1887.

In the last pages of his diary, Henderson lists names, locations, and dates of baby blessings and baptisms he performed during his mission. He also includes a summary of the letters he sends and receives between 1885 and 1887.