Simple song about two people falling in love in a canoe on the Ohio river. The lyrics were written by Ballard MacDonald, and Mary Earl (real name Robert A. “Bobo” King) set it to music. Ohio adopted it as its state song in 1969.
The song also has a personal significance to Bradbury. On the rainy night after his lengthy visit with the real Mr. Electrico, he stood next to a turning carousel that was playing "Beautiful Ohio" and wept. "I knew something important had happened that day, I just wasn't sure what it was," he recalled later.
See also the Bookmark notes on "Mr. Electrico" in chapter 7 (page 34 in this edition); and "Just tell me I'll live forever," in chapter 28 (page 144 of this edition).