Miss. Code Ann. § 27-31-21

All public libraries and buildings in which the free public schools are taught, and the lots on which same are situated, not exceeding four (4) acres in dimensions, without cost to the state or any county or municipality thereof for rent or lease, and also the real and personal property of library associations, used for library purposes where no dividends are declared, and to which the children attending the public schools have free access, shall be exempt from all state, county, and municipal taxes.