There is a Dummy Hoy myth.

One source said he hit the first grand slam homer in
the American League. This is not true.

What is true is that he hit the second grand slam in
the American League – but with an explanation.

His teammate Herm McFarland hit the first grand slam,
but later on in that game, Hoy hit the second
grand slam!

Both grand slams took place in 1901, the first year
of the American League. He was 39 years old, and only
hit two homers that season.