There was a time when control of a person's life rested close home. There was local government for issues very close to home, something that was larger than himself but still something that a person could feel that he had some influence over. There was state government for things a bit further away from home and a bit further out of his control. Finally there was the federal government, the home of the most distant control, the residence of things specified in the constitution.
A bank was a local institution that knew the ins and outs of its community of residence. Locals invested in the banks trusting that the money that was put on deposit there would finance things that he would have some knowledge of and would contribute, fot the most part, to the wellbeing and growth of the local community. Bankers could make decisions that were appropriate to their needs. Different banks could make different decisions. Some banks would be able to pay more interest than others because, for the most part, the decisions that they made were better than the decisions of other banks.
In those days there was this marvelous, functioning system of loaning money to those who the bank thought were a good risk. Money to buy a private home. Before that home ownership was much more illusive. Either a person managed to get a home through an inheritance, through the sweat of his own brow by building it himself or saving enough money to pay for it outright in the beginning,
The invention of this locally-based home mortgage system changed all that. Now all someone had to do was work and save 20% of the needed amount, have a job that could support the monthly payments and apply for the loan. There were racial inequities for certain but people from all races, all Americans, managed to be able to attain a mortgage for a home of their own. The strength of a home buyer's conviction to save a 20% downpayment was one of the assurances that the bank had that the loan would be paid. No one except for the most desperate would abandon a home leaving 20% of their money behind. Every home buyer had some skin in the game and this was a very good thing.