[5] Under the guidance of future College Football Hall of Fame coach Grant Teaff, Marcum started the 1965 and 67 seasons for the Indians, leading them to a 5–13–2 record.
Not waiting for the Dynamite to resume operations (which they later did for three years starting in 1989), he then went on to coach the Detroit Drive for that team's entire existence save 1990, when he was an assistant with the University of Florida.
However, this team likewise folded, but Marcum's success with them became the basis for his hiring and tenure with the most successful Arena team ever, the Tampa Bay Storm, where he achieved his greatest fame, and arguably the greatest fame of any Arena coach (as of 2014), winning four more ArenaBowl championships, including another back-to-back run (1995 and 1996).
His resignation came after it was revealed that in a deposition given in a lawsuit between himself and former team owner Robert Nucci, Marcum had admitted to receiving and forwarding via his work e-mail account material that was pornographic and racially insensitive.
[9] The Arena Football League dedicated its 2014 Hall of Fame Weekend to Marcum's memory, with each player uniform bearing a navy and gold "TM" patch.