To qualify as a candidate for the office of United States Senator, the person must be at least 30 years old, must reside in the state from which he or she is elected, and must have been a U.S. citizen for a minimum of 9 years. These requirements are set forth in the U.S. Constitution.
Inspired by British precedents, delegates to the 1787 Constitutional Convention set membership requirements for both the House of Representatives and the Senate. These requirements included age, citizenship and residential qualifications. The delegates specifically left out property ownership and religious requirements. While British law of the time banned anyone born outside England, Ireland or Scotland from sitting in Parliament, the newness of the American colonies, and the fact that nearly everyone at the time came from somewhere else, necessitated the looser residential and citizenship limitations for the U.S. Congress.