Campbell was known as an authority on Celtic folklore Its origins lay in
Popular Tales from the Norse (1859) by his friend
George Webbe Dasent. Reading Dasent's book, Campbell realised that he had heard Gaelic versions of some of the stories when young. He organised extensive
fieldwork to collect Gaelic tales, and edited some of the resulting corpus for publication: a substantial part of the research remained unpublished at the time. He dedicated
Popular Tales of the West Highlands to the
Marquess of Lorne, son of George Campbell, 8th Duke of Argyll. Among the recruits to Campbell's collecting team was
Alexander Carmichael. Campbell supported
Francis James Child's interest in collecting traditional
ballads in a number of ways, from sending ballads collected through fieldwork to providing introductions.
Leabhar na Feinne In 1872 Campbell self-published
Leabhar na Feinne, a collection of heroic ballads culled from manuscripts held by libraries, but to his chagrin this endeavour failed to meet with success.
The Celtic Dragon Myth The Celtic Dragon Myth was published posthumously in 1911. Campbell had started preliminary work on
The Celtic Dragon Myth in 1862, and work intensified on it from 1870 until 1884. After Campbell's death in 1885 the noted Gaelic scholar
George Henderson contributed some translation work, provided an introduction, and completed the editing of the manuscript for its eventual publication in 1911.
Other works •
A Short American Tramp in the Fall of 1864 (1865) •
Frost and Fire: Natural Engines, Tool-Marks and Chips (1865, 2 vols.) •
My Circular Notes: Extracts From Journals, Letters Sent Home, Geological and Other Notes, Written While Travelling Westwards Round the World, From July 6, 1874 to July 6, 1875 (1876) •
Canntaireachd: Articulate Music (1880) •
Thermography (1883). == Travel ==