These parks became an important part of the plan for the reconstruction of Paris drawn up by Napoleon III and his new Prefect of the Seine, Baron Georges-Eugène Haussmann. The Haussmann plan called for improving the city's traffic circulation by building new boulevards; improving the city's health by building a new water distribution system and sewers; and creating green spaces and recreation for Paris' rapidly growing population. In 1852, Napoleon donated the land for the Bois de Boulogne and for the Bois de Vincennes, which both belonged officially to him. Additional land in the plain of Longchamp, the site of the Château de Madrid, the Château de Bagatelle, and its gardens were purchased and attached to the proposed park, so it could extend all the way to the Seine. Construction was funded out of the state budget, supplemented by selling building lots along the north end of the Bois, in Neuilly.