Maryland Constitution of 1867 Art. 11, § 5

No person, elected and qualified as Mayor, or as a member of the City Council, shall, during the term for which he was elected, hold any other office of profit or trust, created, or to be created, by the Mayor and City Council of Baltimore, or by any Law relating to the Corporation of Baltimore, or hold any employment, or position, the compensation of which shall be paid, directly or indirectly, out of the City Treasury; nor shall any such person be interested, directly or indirectly, in any contract, to which the City is a party; nor shall it be lawful for any person, holding any office, under the City, to be interested, while holding such office, in any contract, to which the City is a party.