Guarantee Electrical Company lights up St. Louis as one of the oldest and largest full-service electrical contractors in the nation. 2002 marks our 100th year —our centennial. Guarantee was founded in 1902 by a young group of entrepreneurs to wire the St. Louis 1904 World's Fair. Today, Guarantee boasts a 600 person staff comprised of professional engineers, project managers and IBEW electricians who meet all your electrical construction, design/build, communications, data, service and maintenance needs.