“Sport” as an informal appellation

Question

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?

Answer 1

Google Ngram viewer shows that its use peaked "in that way" between 1919 and 1937. Here's an example from 1915: "And pushed me to my fall. I was a young man, and the gay world called me to come. Gay women and gay men called to me. crying: 'Be a sport: lac a good sport! Fill our glasses and let us fill yours. We are young but once; let us dance and sing ...'"

The best source for early usages would be the Oxford English Dictionary.