What Is A Livery Barn Keeper?

A livery barn is a barn that specializes in renting out horses, boarding horses and seeing that the appropriate care is maintained (new shoes, feeding, etc). The keeper is the person who runs the stable.
The term is not in use much as people now drive cars.  Those that ride horses have their own facilities or board at stables that general have a speciality as to what the horses are used for such as racing stables or show stables.  The high cost of insurance that the owner must pay in case a rider gets injured as eliminated many barns that rent horses to people.   Also, many stables are being put out of business due to high taxes on property.  "Attractive nuisance laws" are often enacted by people who build housing developments around barns and then want to get rid of the "nasty, dirty horses" who were there first.