“Before, you actually had to pick up a book and read it, the whole thing”
In case I wasn’t clear, my point is that a lot of people derive their knowledge of writers big and small not by reading whole books, but by reading excerpts in other (possibly lesser) articles and books. For instance, most people know of Darwin through the Neo-Darwinism of the mid and latter 20th century. Or maybe (just maybe) through recaps of Herbert Spencer’s popularization. Who the heck bothers with “On the Origin of the Species”? Likewise, our Schopenhauer is Nietzsche’s Schopenhauer, our Hegel is Marx’s Hegel, our Sophocles is Freud’s Sophocles, and (most relevant to us) our Edmund Burke is the 20th century American conservative movement’s (and especially Russell Kirk’s) Edmund Burke.
Obviously there was a time when people read more whole books, but there was never a golden age when everyone knew firsthand what everyone else was talking about.
While I understand and agree with what you said about (many) people only knowing the classics through the interpretive works of others, I'm not entirely sure that there wasn't a "Golden Age" in our Republic, at least very early on.
If you read McCullough's "John Adams" (and I suspect you have), you can see countless letters and transcripts cited where Adams (and his colleagues) discuss in great detail not only contemporaries like Tocqueville and Adam Sith, but Socrates and Cicero and other Roman historians and statesmen. It's clear that the Founding Fathers were incredibly well read, and well read on the source material.
I'm not sure when that ended in American history, but it certainly did end, and the internet has only made it worse.