Established by the Texas Legislature in 1891, it is the state's oldest regulatory agency and began as part of the Efficiency Movement of the Progressive Era. From the 1930s to the 1960s it largely set world oil prices, but was displaced by OPEC (Organization of Petroleum Exporting Countries) after 1973. In 1984, the federal government took over transportation regulation for railroads, trucking and buses, but the Railroad Commission kept its name.