During the Constitutional Convention of 1787, delegates Elbridge Gerry and George Mason proposed adding a bill of rights to preface the U.S. Constitution, but this idea was unanimously rejected by the State delegations. Due to this rejection, both refused to sign the U.S. Constitution.
Over time, numerous delegates took a different stance on the matter. In fall 1789, James Madison introduced his 12 proposed amendments to the U.S. Constitution, which were heavily influenced by the English Bill of Rights of 1689 and George Mason’s Virginia Declaration of Rights. Then, on September 25, 1789, the First Federal Congress approved them and sent it to the states to ratify.
Two-thirds of the states ratified 10 of the 12 amendments by December 1791, making the Bill of Rights the law of the land. The first of the two amendments that weren’t ratified discussed the size of electoral districts and has yet to be ratified. The second prohibits pay raises for Congress members until the next election takes place and was ratified in 1992 as the 27th amendment.