Historical research of public spaces provides a better understanding of the social formation and preserve cultural and landscaping heritage. José Bonifácio Square, located in Picacicaba, São Paulo State, Brazil, is an important public space. We carried out a historical survey in the archives of municipal public institutions and a landscape record was done by identifying tree species implanted in the square. We verified a strong church influence in the development of the square landscape project. The first landscaping work occurred in 1885, and it became known as City Public Garden. It presented naturalistic features, using exotic and native species, mainly trees, for landscaping composition. Several modifications and reforms were made from 1885 to 2005. José Bonifácio Square was considered highly diverse (H’ = 3.18) with 151 individuals, distributed in 36 species belonging to 14 botanical families. The native species from Atlantic Forest represented 82.6% of Bignoniaceae, Arecaceae, and Fabaceae species. The high diversity of native species found in José Bonifácio Square allowed us to infer a lower ecological fragility and a higher environmental balance than other Brazilian squares. The analysis of historical information from the years 1885 to 2019 and the analysis of the square’s floristic composition in contemporary times demonstrated José Bonifácio Square’s relevance in forming and conserving Piracicaba’s urban identity.