BoingBoing and Michael Geist point to a New York Times article from 1897 about Canadian "pirates" selling sheet music across the border to Americans at a cheaper price than what American music publishers were charging.
By 1897 the Americans had finally come to recognize the copyrights of foreign authors from some countries. But in 1897 this policy was only a few years old. Until 1891 the US did not recognize international copyright. Up to that year, American publishers did an excellent trade selling "pirated" editions of British books across the border to Canadians.
A lot has changed since then. In the nineteenth century, the Americans were the pirates and the Canadians - well, we had our pirates too, but we operated under international copyright as a British dominion much earlier: from 1886 under Britain's International Copyright Act and even earlier under the 1842 Imperial Copyright Act and various bilateral treaties that applied throughout the British Empire. In fact (see inset), in 1888 the idea was floated that the Canadians might try to pressure the Americans to recognize international copyright as a part of an agreement on the Alaskan border dispute. That didn't get far.
The Globe, Feb 15 1888
