In an earlier post I sketched some of the milestones in cheap book publishing. Another cheap-book breakthrough was made in 1774 in England when the copyright law of 1709 finally came into force (earlier, the book traders and the courts had simply ignored the law and enforced their own copyright claims) in the momentous court decision Donaldson v. Beckett:
Among the chief offenders [of book piracy] was Alexander Donaldson, the “bold Robin Hood” to whom Boswell’s uncle drank a genial health in 1763. In 1774 Donaldson appealed to the House of Lords a Chancery decision forbidding him to publish or sell Thomson’s Seasons, a book which, under the law, had moved into the public domain. In one of the most momentous decisions in book-trade history (Donaldson v. Beckett) the concept of perpetual copyright was finally killed; copyright, the Lords held, ended when the Act of 1709 said it did. [i.e. 21 years in case of books already published and 28 years in future books] Now, for the first time, any book whose copyright had expired could be reprinted as cheaply as a publisher was able, without fear of legal complications. The consequences to the mass reading public are almost incalculable. (Altick, 53-54)
Among the beneficiaries of the case were 18th century book entrepreneurs such as John Bell, Alexander Hogg and John Cooke. According to Thomas Bonnell, Bell’s The Poets of Great Britain Complete from Chaucer to Churchill not only made English poetry available to a wider audience, but also helped shape a canon of English poetry:
“The Plan of this undertaking,” Bell announced, was “to furnish the public with the most beautiful, the correctest, the cheapest, and the only complete uniform edition of the British Poets.” The projected one hundred volumes were to represent “all the British Poets from the time of Chaucer to Churchill” (MC, April 14, 1777). The new edition would, according to Bell, fill an obvious void. Booksellers, he explained, had long vied for distinction in publishing the Greek and Latin classics; consequently it was rather easy to obtain a set of the ancient classics. To collect the English poets was, by contrast, a “business of time, difficulty, and vast expense,” even for residents of London, and to collect them “uniformly printed, so as to appear in a library as one and the same book,” was out of the question. Italy and France, Bell claimed, had already “rewarded the memories of their illustrious countrymen” by publishing uniform editions of their works. Unaccountably negli- gent by comparison, Great Britain had yet to honor her own worthies, to recognize them in “a general and uniform publication” as “English classics.” Bell’s Poets, the prospectus assured, would answer this need.8 If one considers Bell’s explicit design, the great size of his undertaking, and his pointed and persistent advertising, then the significance of the Poets becomes clear: it was the first serious attempt to publish a comprehensive English literary canon. (Bonnell, 130)
Bell’s business model for the Poets took its inspiration from the House of Elzevier, who had pioneered the publication of cheap classics:
Before we proceed, two aspects of Bell’s plan are worth pausing over. First, Bell alludes to the Elseviers, the seventeenth-century Dutch booksellers renowned for printing, with high typographical standards, reliable yet inexpensive classical texts in a small format. Without claiming more than a likeness in size, Bell associates his enterprise with these famous imprints. Was this an illegitimate advertising ploy? Without pushing the comparison, we may grant the young bookseller a place in the tradition he invokes, that of promoting a “classical” literature through small and relatively inexpensive volumes. Among the obvious differences between the Elseviers and Bell is the market each served: whereas the Dutch with their Latin classics largely served university needs, Bell took his English classics to a broader public. (Bonnell, 139)
Altick, Richard D. The English Common Reader. A Social History of the Mass Reading Public 1800-1900.  Chicago and London: Phoenix Books, 1963.
Bonnell, Thomas F. “John Bell’s ‘Poets of Great Britain:’ The ‘Little Trifling’ Edition Revisited.” Modern Philology 85.2 (1987): 128-152.