Miss. Code Ann. § 27-35-501: Miss. Code Ann. § 27-35-501

It shall be the duty of the Commissioner of Revenue, constituting the state assessor of railroads and other public service corporations, to annually assess for taxation the property of the persons, firms, partnerships, companies, associations, or corporations, as hereinafter defined, engaged in the business of operating, furnishing or leasing cars for the transportation of freight, or to be used in the operation of any railway line or lines wholly or partially within this state.