>When did the term, intellectual property, first appear?
Doing a quick scan through Supreme Court decisions, a pretty isolated example is a mention in the 1873 case, Mitchell v. Tilghman, 86 U.S. 287, where the opinion quotes a letter using the phrase.
Other that that isolated mention, the phrase does not appear in a Supreme Court decision until 1949 in . C.I.R. v. Wodehouse, 337 U.S. 369.
There is a lower federal court decision from 1845 in MassDavoll v. Brown, 1 Woodb. & M. 53, 3 West.L.J. 151,, that mentions the phrase. Here is what the court says in the course of a patent dispute: "These principles, however, are not inconsistent with another one, equally well settled, which is, that a liberal construction is to be given to a patent, and inventors sustained, if practicable, without a departure from sound principles. Only thus can ingenuity and perseverance be encouraged to exert themselves in this way usefully to the community; and only in this way can we protect intellectual property, the labors of the mind, productions and interests as much a man's own, and as much the fruit of his honest industry, as the wheat he cultivates, or the flocks he rears."
Hope that helps
-- Nathan