 The school moved several times and was housed in three different locations in its first three years before returning again to the original townhouse building on Courtland Street . Finally , in 1843 , the City Council allocated $ 23 @,@ 000 to acquire the vacant old landmark Assembly Rooms structure at the northeastern corner of East Fayette and Holliday Streets for the school . The famous Assembly Rooms also served as the intellectual and educational center of town , with the upper floors holding rooms where the new Library Company of Baltimore and the later Mercantile Library were located for several years . In 1850 , the City Council granted the Board of School Commissioners the right to confer graduates of the decade old high school with certificates of graduation , and the following year the school held its first commencement ceremony . 
