In 1790, copyright term in the US was 14 years (if registered) plus 14 more years (if renewed), for a maximum total of 28 years. As of 1998, the copyright term is 95 years after publication (or 75 years after the author's death). So if creativity is equally as difficult now as it was in the past, I would ask why copyright terms have been so substantially expanded.

It's also worth pointing out that, since the vast majority of works generate almost all their profits within the first few years of publication, such a lengthy copyright term primarily benefits rights holders of the extremely elite set of works that remain popular after decades of publication. In practice, this mostly winds up being companies like Disney, Sony, Universal, and so on. Meanwhile, the group that is most directly harmed is not the public in general, but everyday artists—who are less free than they were in the past to build on previous works, remix them, or use them as supporting elements in a larger project.

Consider that, whereas consumers wanting to enjoy an older (let's say WWII-era) work usually face a choice between paying a small fee and getting an unauthorized copy somehow, creators face a choice between enduring a difficult and extremely costly licensing ordeal or opening themselves up to substantial legal risk. Creators often lose heart when faced with this dilemma—and many projects, at least a few of which would probably have been great, will never be made because of this.