Much of the area that is Rua 25 de Março today was originally part of the Tamanduateí River. A series of river engineering projects in the late nineteenth and earlier twentieth centuries realigned the Tamanduateí and Anhangabaú rivers, moving the river and the port further to the east. The old port, Porto Geral, lends its name to one of the major cross streets of 25 de Março, Ladeira Porto Geral. The original street name, "Rua de Baixo", refers to the low ("baixo") position of the land in comparison with the streets uphill to the west. In 1865 the name change was changed to commemorate the date of Brazil's first constitution, signed on 25 March 1824.