I was watching a film ostensibly set during the American Progressive Era (1900 to 1918 or so), in which two teenaged boys used the line
"Ah, be a sport, Charlie!"
That got me to thinking, was the term "sport" or "be a sport" in use in that way, that early? Around which time did the word "sport" become used to describe, as my dictionary puts it, behavior in a "good or specified way" in response to teasing or defeat?
What resources could I use to learn the answer to that question?