From 1920 to 1922, under Carlos Sampaio, Morro do Castelo (Castle Hill) and the poorest district of the city, Misericórdia (Mercy), were demolished in an attempt to improve hygiene, beautify the region and increase economic prosperity.

Misericórdia was one of the only official low-income districts that had survived Pereira Passos' reforms, and it had hence attracted a large number of the homeless from demolished regions.

named after the french urbanist alfred agache, who now participated in the improvement of the original Plano de Remodelação, Extensão e Embelezamento da Cidade do Rio de Janeiro, The Plano Agache (Agache Plan) was developed throughout this decade and completed in 1930, under the then governor of the state Antônio da Silva Prado Júnior - The aim of the plan was to transform the city into a spectacle of great development, organization and beauty.