A copy of the Constitution of the Republic of Texas was included with the declaration of independence. The constitution borrowed language from the US Constitution and the constitutions of several southern states. It formed a unitary republic, rather than the federal republic as defined in the US Constitution. The President of the Republic of Texas had a three-year term and could not serve another consecutive term, which was based on provisions in the Mexican Constitution. The Texas Constitution also protected the right to own slaves and prohibited "Indians" and "Africans" from living freely in the country and from becoming Texan citizens.