Despite these positive legislative developments, however, the authority resisted the urge to regulate offline casino gambling for the remainder of the 20th century.Ģ008 This changed in 2008, however, when a constitutional referendum approved the installation of slot machines at five privately owned facilities in Maryland. The state was also amongst the first to legalize bingo in the states (in 1952), although it should be noted that this discipline faces a number of restrictions and can only be conducted by charitable organizations.ġ972 A state lottery in Maryland was fully legalized in 1972, and this remains available to all state residents aged 18 or over. 1920 Maryland has always been synonymous with pari-mutuel horse racing wagering, with this practice having been regulated way back in 1870 and formally legalized in 1920.