Modern attempts at renewal began in the late 19th century in developed nations, and experienced an intense phase in the late 1940s under the rubric of reconstruction. The process has had a major impact on many urban landscapes and has played an important role in the history and demographics of cities around the world.
Urban renewal or regeneration is a process where privately owned properties within a designated renewal area are purchased or taken by a municipal redevelopment authority, razed and then reconvened to selected developers who devote them to other uses.
The concept of urban renewal as a method for social reform emerged in England as a reaction to the increasingly cramped and unsanitary conditions of the urban poor in the rapidly industrializing cities of the 19th century. The agenda that emerged was a progressive doctrine that assumed better housing conditions would reform its residents morally and economically. Another style of reform – imposed by the state for reasons of aesthetics and efficiency – could be said to have begun in 1853, with the recruitment of Baron Haussmann by Napoleon III with the redevelopment of Paris.