BOSTON--(BUSINESS WIRE)--American Tower Corporation (NYSE:AMT) today reported financial results for the quarter ended March 31, 2015. Jim Taiclet, American Tower's Chief Executive Officer stated, "Our U.S. and international operations maintained strong leasing momentum through the first quarter of 2015, driving global Organic Core Growth of over 9%. We also completed the largest tower transaction in the domestic tower industry’s history by adding over 11,400 Verizon assets to our portfolio. Add