Dandelion Wine is set in Green Town, Illinois, which is the thinly disguised Waukegan, Illinois. Bradbury was born in Waukegan, and kept returning there as his father changed jobs. Bradbury did, indeed, spend the summer of 1928 in Waukegan, in the small house next door to his grandparents' large home.
In the Dandelion Wine introduction Bradbury wrote in 1974 (35 years ago!) he mentions a critic who analyzed Dandelion Wine and the more realistic Main Street, by Sinclair Lewis. The critic wondered
how I could have been born and raised in Waukegan... and not noticed how ugly the harbor was and how depressing the coal docks and railyards down below the town. ...Trains and boxcars and the smell of coal and fire are not ugly to children.... Counting boxcars is a prime activity of boys. ...And... that supposedly ugly railyard was where carnivals and circuses arrived with elephants.... As for coal from the docks, I went dow in my basement every autumn to await the arrival of the truck and its metal chute, which clanged down and released a ton of beauteous meteors that fell out of far space into my cellar and threatened to bury me beneath dark treasures.The characters hardly need to be listed. They include Douglas Spaulding and his brother Tom. His parents, grandparents and great-grandma. "All the old people": Miss Helen Loomis, colonel Freeleigh, Miss Bentley. Mr. Triddan the trolley driver. John Huff and Charlie Woodman, his friends. And, all the other people living in Green Town.