Correcting Guam's History in the PACT Act This bill expands eligibility for a presumption of service-connection for specified diseases associated with exposure to certain herbicide agents. Under a presumption of service-connection, specific conditions diagnosed in certain veterans are presumed to have been caused by the circumstances of their military service. Health care benefits and disability compensation may then be awarded. Under the bill, service performed in Guam or its territorial waters between August 15, 1958, and July 31, 1980, provides a veteran who has a specified disease that is associated with exposure to certain herbicide agents with eligibility for a presumption of service-connection. (Under current law, the eligible time frame for service in Guam is between January 9, 1962, and July 31, 1980.)