Florida has long been a beacon for retirees, but for many, the American dream of owning a home there was a fantasy. That changed in the 1950s, when the so-called "installment land sales industry" hawked billions of dollars of Florida residential property, sight unseen, to retiring northerners. For only $10 down and $10 a month, working-class pensioners could buy a piece of the Florida dream: a graded home site that would be waiting for them in a planned...