He associated with the antiquarians Joseph Kilner and Samuel Rudder, and in 1784 was elected a Fellow of the Society of Antiquaries of London, backed by Daines Barrington, William Boys and Edward Hasted.
While the history was heavily criticised for a lack of original research in the Gentleman's Magazine on publication,[4] it has subsequently been widely acknowledged as an ingenious work[5] that made substantial advances in Domesday nomenclature, and contains valuable records of church monument inscriptions, many of which have since been lost.
[6] That it is in large part a skilful collation and synthesis of existing historical sources, supported by some research and a deep first-hand knowledge of the county, was acknowledged by Collinson in his introduction.
[6] Collinson's immense, historically important achievement was freely acknowledged almost a century later by Robert William Eyton who praised the historian's topographical knowledge, scholarship, utmost precision and constancy.
Frederic William Weaver and E. H. Bates just over a century later in 1898, which greatly facilitates the use of the work as well as updating and standardising the spelling of place names.
He also left a legacy to his sister, Elizabeth Collinson, of a ring and thirty pounds to be raised from the sale of the copyright of the History of Somerset.
However at the administration of the will in 1798, Timothy Stevens, a bookseller of Cirencester and one of the original subscribers to the History of Somerset, came forward as a creditor and was granted all of Collinson's goods and chattels.