When did “amateur” take on the sense of someone who performs an activity without compensation, as contrasted with a “professional” who is paid to do it? I have several mentions in the early-mid 1860s of early baseball clubs fielding their “amateurs” where the context suggests this means their less capable members, who presumably also devote less time to the game than their best players. The dating is such that I doubt this is intended to suggest that the better players are paid. This makes sense if we take “amateur” to mean persons playing simply for the love of the game, with a hint of “even though they stink”. In the 1870s “amateur” ballplayers are as contrasted with professionals, with the amateurs at least in theory not receiving compensation.
I am wondering if there was a similar development of senses of “amateur” apart from baseball, and if so when?