I'm pretty sure this is just a traditional tune, but if there's anybody I should be giving credit for the words and/or music, please let me know.
Lyrics
I've got a mule and her name is Sal
Fifteen miles on the Erie Canal
She's a good old worker and a good old pal
Fifteen miles on the Erie Canal
We've pulled some barges in our day
Filled with lumber, coal, and hay
And we know every inch of the way
From Albany to Buffalo-o
Chorus
Low bridge, everybody down
Low bridge, for we're coming to a town
You can always know your neighbor,
Can always tell your pal
If you've ever naviaged on the Erie Canal
We'd better get along on our way, old gal
Fifteen miles on the Erie Canal
'Cause you bet your life I'd never part with Sal
Fifteen miles on the Erie Canal
Git up there mule, here comes a lock
We'll make Rome 'bout six o'clock
One more trip and back we'll go
Right back home to Buffalo
Chorus
This song is best performed by someone with a nice deep rumbling bass voice, especially the line "From Albany to Buffalo-o", which dips down to the lowest note in the tune. I've found it's a good introduction to the idea of songs in a minor key for little kids learning music.