 They have restrained flat roofs; flat, brown or red brick façades; molded and galvanized sheet-metal exterior cornices, often stamped with neoclassical decoration and dressed up with ball finials; stained glass transoms; and marble steps and trim.In the latter half of the 19th century, immigrant European laborers as well as free blacks like Frederick Douglass flocked to Baltimore seeking jobs in the waterfront factories, rail yards and wharves.The architect-designed homes of Bolton Hill and Mount Vernon were beyond their reach, but speculative builders built block upon block of narrow rowhouses on inexpensive land, including around Patterson Park.