The Massachusetts zoning ordinance chapter 40C establishes historic districts across the state. The purpose is to “promote eat educational, cultural, economic, and general welfare” by the preservation of buildings and places with significance to Massachusetts history. In order to establish a historic district, local government meetings and votes take place. The district then undergoes an investigation to gather historic information and the significance of the specific sites. Each district holds a commission of three to seven people who review applications for changes to structural alterations. They also have the ability to prevent demolitions when possible and prevent inappropriate changes.