[schoen]

The first sale doctrine is statutory as well as judicial. See 17 USC §109 (http://www.law.cornell.edu/uscode/text/17/109).

§109 was part of the 1976 Copyright Act, so first sale has been codified in statute for 36 years.

I don't think the Copyright Act suggests that every purchase of a medium containing a copy of a copyrighted work should be treated as a license rather than a sale. Instead, it says (§106) that the copyright holder "has the exclusive rights to do and to authorize" six particular acts in relation to the work, independently of having sold a particular copy (but not, apparently, other acts).