Here's an excerpt:
This article reconsiders the history of copyright’s pivotal fair use doctrine. The history of fair use does not in fact begin with early American cases such as Folsom v. Marsh in 1841, as most accounts assume—the complete history of the fair use doctrine begins with over a century of copyright litigation in the English courts. Reviewing this "pre-history" of the American fair use doctrine leads to three significant conclusions. The first is that copyright and fair use evolved together. Virtually from its inception, statutory copyright went well beyond merely mechanical acts of reproduction and was defined by the concept of fair abridgment. The second insight gained by extending our historical view is that there is in fact substantial continuity between fair abridgment in the pre-modern era and fair use in the United States today. These findings have substantial implications for copyright law today, the principal one being that fair use is central to the formulation of copyright, and not a mere exception.
The third conclusion relates to the contribution of Folsom v. Marsh itself. The pre-modern cases illustrate a half-formed notion of the derivative right: unauthorized derivatives could be enjoined to defend the market of the original work, but they did not constitute a separate market unto themselves. Folsom departs from the earlier English cases in that it recognizes derivatives as inherently valuable, not just a thing to be enjoined to defend the original work against substitution. . . . It seems likely that as more and more derivatives were enjoined defensively, courts and copyright owners began to see these derivatives as part of the author’s inherent rights in relation to his creation. In other words, once copyright owners were allowed to preclude derivatives to prevent competition with their original works, they quickly grew bold enough to assert an exclusive right in derivative works for their own sake.