What is probably barely remembered today is that during much of the heyday of the store's delivery service, horse-drawn wagons were used:
In those days, it was not unknown for retailers to whip horses and flog them, sometimes even to death. According to Give the Lady What She Wants, Field had different ideas. He made cruelty to horses grounds for dismissal. On the very hottest days, horses had to rest (young boys strapped packages to their backs instead). Horses only worked half a day, even if that meant a driver had to leave his horse at a neighborhood stable and go back for another horse so he could finish his deliveries.
I would love to locate a photograph of signs in the Marshall Field's barns that read “Don’t whip the horses!”