– 222 attendees Alan Dean Foster – Guest of Honor Marcon XI 1976 – 212 attendees Joe Haldeman – Guest of Honor Marcon X 1975 – Approximately 185 attendees James E. Gunn – Guest of Honor Marcon IX 1974 – Approximately 170 attendees Hal Clement – Guest of Honor Andrew J. Offutt – Toastmaster Marcon VIII 1973 – Approximately 100 attendees Anne McCaffrey – Guest of Honor Marcon VII 1972 – Approximately 150 attendees Roger Zelazny – Guest of Honor Marcon VI 1971 – Approximately 120 attendees Lester del Rey – Guest of Honor Marcon V 1970 – Approximately 105 attendees Gordon R. Dickson – Guest of Honor 1960s Marcon IV 1969 – Approximately 100 attendees Terry Carr – Guest of Honor Marcon III 1968 (First time in Columbus) – Approximately 85 attendees Frederik Pohl – Guest of Honor Marcon II 1967 (Toledo) – Approximately 60 attendees Marcon I 1966 (Toledo) – Approximately 20 attendees Roger Zelazny – Unofficial Guest of Honor References External links Marcon official website Science fiction conventions in the United States Science fiction organizations