I came across a 1957 NYT article that mentioned a "four-run homer." I started thinking, When did they first start calling them "grand slams"? I started looking through articles from the early years of baseball. Not much use of the term (which comes from the card game Bridge) until the 1920s. Before that, it was used, but it was referring to a four-game sweep or other foursomes. Or just slams that were grand--they talk about a four-run inning in the 1919 World Series as "one grand slam," though all four runs did not score on a homer.

In 1929, the Times said "...thus producing what is known in baseball as a grand slam is enough to make a ball game momentous." It was Les Bell of the Boston Braves who hit the pinch grand dong they were referring to. So that gives you the impression that it was a new term then.

In 1938, The Sporting News said "...slammed a four-run round-tripper over the distant left field wall in Pittsburgh. That one Grand Slam appeared to be just what the doctor ordered for the Italian boy." (Johnny Rizzo--the sub-headline also uses grand slam, funny how it's capitalized in the story. They also call the Pirates the "Freebooters" in that article. I love these old baseball descriptions....)

By the early '40s, articles are chock full of references to grand slams.

I did find one instance of the term "grand slam home run" from before the late-30s, and it was from the Marion Star circa 1916: "Eric Tipton's eighth inning grand slam home run yesterday put St. Paul right on the heels of Minneapolis for the American Association lead."

So what did I learn? That's it's almost 2 AM and I'm getting tired. This is not a definitive history. If you've got anything to add, feel free.