Fair use was designed for teachers photocopying pages of Walden for their pupils to read over the weekend. Not industrial-scale laundering of IP to benefit shareholders.
Walden was first published in 1854. At the time, the maximum length of copyright in the US was 28 years (14 at first + 14 on renewal).
Notions of "fair use" in the US can be traced back to the mid-1800s, too. There were court rulings, but fair use was not codified into law until 1976. Non-profit educational use was explicitly called out in 1976 also.
Photocopiers were first patented in 1937.