Surprise! If you were a particularly lucky kid in the early 1920s you might have found one of these in your life:
Open the box and look inside:
Yep, baseball and boxing cards. Not my stuff, just some illustrative images. More pics:
Ruth-Johnson-Sisler-Alexander
Two guys I haven't ID'd yet (top row) and Johnny Kilbane and Benny Leonard (bottom row).
There were some nonsports cards too but, frankly, who cares, you know?