The Galactic Constitution was the constitution of the Galactic Republic. The Constitution was drafted prior to the formation of the Republic with help from multiple people, including Jonathan Bac, who became the first Supreme Chancellor of the Galactic Republic.
The Rights of Sentience clause was a part of the Constitution that governed the treatment of all sentient species, but specifically non-Human citizens, in the Republic. The clause outlawed humanocentrism, though it still existed in the Republic through the use of non-Human slaves by Human-led Republic companies on fringe worlds, as well as the Outer Rim Territories. Some Republic worlds would also give preferential treatment to Humans over non-Humans.