The Bill of Rights is the first 10 amendments to the U.S. Constitution, adopted as a single unit in 1791. It spells out the rights of the people of the United States in relation to their government.Three delegates to the Constitutional Convention, most prominently George Mason, did not sign the U.S. Constitution largely because it lacked a bill of rights. He was among those arguing against ratification of the document because of that omission, and several states ratified it only on the understanding that a bill of rights would be quickly added.James Madison drew on the Magna Carta, the English Bill of Rights, and Virginia’s Declaration of Rights, mainly written by George Mason, in drafting 19 amendments, which he submitted to the U.S. House of Representatives on June 8, 1789. The House approved 17 of them and sent it to the U.S. Senate, which approved 12 of them on September 25. Ten were ratified by the states and became law on December 15, 1791.