Maryland Constitution of 1867 Art. 11-A, § 4

From and after the adoption of a charter under the provisions of this Article by the City of Baltimore or any County of this State, no public local law shall be enacted by the General Assembly for said City or County on any subject covered by the express powers granted as above provided. Any law so drawn as to apply to two or more of the geographical sub-divisions of this State shall not be deemed a Local Law, within the meaning of this Act. The term “geographical sub-division” herein used shall be taken to mean the City of Baltimore or any of the Counties of this State.