They mandated you be a citizen of the U.S for seven years 25+, and live in the state they represent before becoming a member of the house to keep the house as close to the people as possible. The person has some sort of relatability with the people in that state/ community which makes them likable. Them being a U.S citizen for at least 7 years gave immigrants an opportunity to become a member as well and wouldn’t scare away immigrants wanting to come to the U.S.