In the early days of baseball, team nicknames were much more casual than they are now, when they are considered “brands.”
The team we now know as the Chicago Cubs was originally known as the “White Stockings,” though that was far from an official nickname. (And when the team abandoned being called that, it was picked up by the new American League South Side team after 1900. Otherwise we’d all be White Sox fans now.)
Per baseball-reference’s Cubs franchise page, the Chicago National League Ball Club (as many of us heard it referred to years ago) was known as the Colts around 1890, largely due to an influx of young players, and then after longtime team manager Cap Anson retired after 1897, some began to call them “Orphans.