Rhode Island was one of the original Thirteen Colonies , and became a state ( agreed to the new Constitution ) in 1790 . Rhode Island was the first of the thirteen colonies to renounce its allegiance to the British Crown , on May 4 , 1776 . It was also the last colony of the thirteen colonies to ratify the United States Constitution on May 29 , 1790 , once assurances were made that a Bill of Rights would become part of the Constitution .