From 1879 to the late 1970s, Major League Baseball players were
subject to the "reserve clause" in a standard player contract.
This essentially meant that teams owned the right for a player
to play for them, like property. Players couldn't voluntarily
leave their teams, they could only be traded. It also meant that
they received only one contract offer. They either took the
offer and played or were forced to sit out. This was a rule very
common in pro sports at the time, originating from when they
were just nascent businesses growing out of organized clubs. In
the late 19th and early 20th centuries, there wasn't much of a
market for pro sports stars. They were making 10 or 50 times the
wages of a blue-collar worker for playing a game in a league
with much less exposure and market power. There wasn't much of a
reason to fight for more money. Many clubs at the time were so
financially fragile, there just wasn't more money to be given.
This is why, in 1922, the U.S. Supreme Court ruled that baseball
was just an