History of At-Will Employment: Created Out of Thin Air?

I'd always heard about how Major League Baseball's exemption from antitrust law was based on a long-ago Supreme Court decision that ruled the sport did not (catch this one: DID NOT) engage in interstate commerce. Funny thing is, no Supreme Court decision since that one nearly 90 years ago has ever overturned its obviously false finding. What I didn't realize until I just read a Personnel Concepts white paper was that at-will employment--the arrangement under which employer and employee are free to part company for any reason at all (except discrimination, which is covered by several laws)--was similarly created by court fiat. (At will, of course, is the concept employers use to keep the fear of termination fresh in their employees' minds, while it provides employees with the cover to quit at any time. Some exchange of equal benefits, huh?) Now, common law at the time held that jobs were agreed to last a minimum of one year both here and in Great Britain, but along came a guy named Horace Wood who wrote a treatise on how the courts had long held that employment was at will, subject to termination at any moment for any reason (no one worried too much about racism and discrimination back in the 19th century). Though Wood pretty much made up his interpretations of case history on employment, after that courts high and low ruled that all employment was at will. Cute achievement by Mr. Wood, this. And the title of his treatise was... Master and Servant. "Get to work, you servants, or I'll fire your asses!" is a concept now enshrined in our nation's jurisprudence.