However, state, national and international government officials and business leaders continue to express their support of the pipeline, which has been operative since 1953 through an easement signed with Michigan. In an amicus brief filed Tuesday, the Chamber of Commerce of the United States of America, the Canadian Chamber of Commerce, and affiliate chambers in Michigan and Ohio, as well as the Wisconsin Manufacturers & Commerce, expressed support for Enbridge and the dual pipeline. Other entities filing amicus briefs in support of the pipeline include the government of Canada; attorneys general of Ohio and Louisiana; and North Americaâs Building Trades Unions (NABTU) and the United Steelworkers of America, AFL-CIO.