This paper describes the members of the Sonora constituent congress (1857-61), and analyzes the debates they held regarding the project for the state's Constitution, which would follow the lines estblished by the 1857 Federal Constitution. It also points out the relations between each legislator's trajectory and politicial affiliation (as far as available sources allow for this), and the proposals he presented during the legislative debates that gave place to the 1861 Constitution of Sonora.