"I met a congressman who claimed that he could introduce me to two people who saw Amelia Earhart"

This quote suggests that Jim Sullivan had a possibility encounter with a congressman who was positive that he might introduce him to 2 individuals that had actually seen Amelia Earhart. This indicates that the congressman had some sort of connection to Earhart, or at least recognized people that had seen her. It is possible that the congressman was a fan of Earhart and had actually done some research into her life and location. Additionally, the congressman may have recognized individuals that had actually seen Earhart personally, or had actually listened to tales concerning her from people that had seen her. Regardless, it is clear that the congressman was certain that he could present Jim Sullivan to two individuals who had actually seen Amelia Earhart.