The world's largest global airline alliances in which United is a founding member was founded when?
United Continental Holdings:  Once completely combined, United became the world's largest airline, as measured by revenue passenger miles. United is a founding member of the Star Alliance. Star Alliance: Star Alliance is one of the world's largest global airline alliances. Founded on 14 May 1997, its current CEO is Jeffrey Goh and its headquarters is located in Frankfurt am Main, Germany.
14 May 1997