I guess "pants" were a correct word but we had the alternative of "trousers" that become the one in popular use here. When you think of it we use the shortened form "pants" for "underpants", which suggests at one time it was clear they were really worn under "pants".
Hoppy has A pant on..
he also wears A spek
he can't see where he's hopping
tis a right old real train wreck
he needs to get get his legs back
in two holes not just one
to walk upright and proper
and maybe even run !!