During the last twenty years of his life, he diligently collected materials for a history of Essex, and visited every town and village in the county (Gough, British Topography, i.
He also made large extracts from Thomas Jekyll's Essex collections, filling, according to Morant, ‘above four hundred’ volumes.
But from a document preserved in the Colchester Museum it appears that Holman himself sold his manuscripts to the vicar of Halstead, and Morant, who was then curate there, was a witness of the sale.
dated 5 September 1769, tells him that Rawlinson bought only the ‘refuse’ of Holman's manuscripts (Nichols, Lit.
Morant, by his own account, had in his possession the larger mass of Holman's papers, from which he derived by far the most valuable part of his volumes.
Holman also compiled in 1715 an ‘exact catalogue’ of the Jekyll MSS., which afterwards belonged to the Anstises, and subsequently came to the library of All Souls’ College, Oxford, where it now is, No.