On a national level, Cahill was one of the more well-known city police chiefs. He was the only police chief to be selected by Lyndon Johnson to serve on the President's Commission on Law Enforcement, in 1965. He impressed FBI Director J. Edgar Hoover, who called him the best public administrator in the entire US, so much that Cahill was one of the two finalists (along with Clarence M. Kelly) for the FBI Director post. He was the only police chief in the country to be on the acclaimed television program, "Meet the Press", and his discernment and articulateness struck everyone, when he appeared as a panelist on February 19, 1967.