Gerry Coffin & Carole King wrote a song that was intended to be a demo for Dee Dee Sharp but their babysitter's demo of the song went so well that they issued it with her, and it went to #1. What was the song and the artist that did it?

That would be 'The Locomotion' - by Little Eva
However, it wasn't on Motown.
I remember the 45, the label was blue, but not Motown blue, I'll get back to you.

Yep, that's the answer. I just took this trivia off of this Music Trivia site -- don't know if it was on the Motown label or it was just classified as "The Motown Sound". Thanks for your answer, Roogalator!