in the 1920s, the coolidge administration formed the advisory committee on city planning and zoning, which undertook as its first task the publication of the standard state zoning enabling act in 1926, model enabling legislation for use by state legislatures. this was followed by publication of the standard city planning enabling act (scpea) in 1928. the scpea covered six subjects: (1) the organization and power of planning commissions, which was directed to prepare and adopt a master plan; (2) the content of the master plan; (3) provisions for a master street plan; (4) provisions for approval of all public improvements by the planning commission; (5) control of private subdivision of land; and (6) provisions for the creation of regional planning commissions.