the first border crossings to american schools began in 1949. the tradition began when the principal of the elementary school in columbus allowed children of one father living in mexico to send his children to the school, and the school district began accepting students living in mexico. at first, the district allowed non-u.s. citizens to attend. around the 1970s luna county began requiring u.s. citizenship in order for children to attend schools, but the district continued accepting children not living in luna county.