IUJAT | Strengthening Workers, Building a Better Future PLEASE CONTACT US TODAY. Forging a New Future for American Labor As the oldest union in continuous existence in the United States the International Union of Journeymen and Allied Trades IUJAT is the embodiment of both tradition and innovation in the labor movement. The IUJAT has thrived by relying on the core principles and values that have kept it strong since 1874 and creating a modern innovative approach to representation in a rapidly changing world. When many other unions have become obsolete the IUJAT continues to survive because we understand and meet the needs and challenges of the American worker in a modern economy.