The Seaboard Football League was a minor American football league that operated from 1971 to 1974.  It folded after the 1974 season as a result of the founding of the World Football League, which deprived the league of talent.
Some of the more notable Seaboard Football league alumni include Vince Papale, who went on to the WFL's Philadelphia Bell and later the NFL's Philadelphia Eagles); Joe Klecko, who "was never paid a penny" for his time and used the opportunity to earn a college scholarship and propel himself into a professional career; wide receiver Jack Dolbin, who later appeared in Super Bowl XII for the Denver Broncos; and King Corcoran, the career minor-league quarterback who would also go on to play for the Bell in the WFL. While players (such as Klecko) could play as amateurs, most players were paid a sum of $50 per game.
During the 1972 season, after the folding of the Atlantic Coast Football League, the Seaboard Football League was the second-highest ranking professional football league in the United States, behind only the NFL. It dropped after the Hartford Knights left for a revived ACFL and the league picked up teams from the semi-pro Empire Football League for play in 1973, before folding. 
The league was founded with eight teams in 1971, five of which came from the Interstate Football League, two from the Mason-Dixon Football League, and one independent.  The teams played a 14 game season, with all games taking place on Saturday nights. In 1972, the Hartford Knights of the ACFL joined the league , going undefeated and winning the championship  then returned to the ACFL for its 1973 season. The Seaboard League again had 8 franchises, but played a ten game season. After the ACFL folded, Bridgeport Jets and the New England Colonials played joined the Seaboard League, which fielded six teams in a shortened 1974 season.
1971 Schuylkill Coal Crackers 13, Hagerstown Bears 0
1974 Wilkes-Barre Bullets 20, Bridgeport Jets 9
- Albany Metro Mallers (NY) (1973) 
- Aston Green Knights (1972-73) / Ridley Township (PA) Knights (1971) (known as the "Green Knights" to distinguish them from the Hartford Knights in 1972)
- Binghamton (NY) Jets (1973)
- Boston Colonials (1974)
- Bridgeport (CT) Jets (1974)
- Bristol (CT) Steelers (1973)
- Chambersburg (PA) Cardinals (1971-74)
- Conshohocken (PA) Steelers (1971-72)
- Frederick (MD) Falcons (1971
- Hagerstown (MD) Bears (1971-73)
- Hartford (CT) Knights, (1972) forced out after a perfect season in 1972
- Long Island (Freeport, NY) Chiefs (1972) 
- Portsmouth (VA) Bucks (1972)
- Reading (PA) Coal Crackers (1972)
- Schuylkill County Coal Crackers (Pottstown PA) (1971) 
- Scranton (PA) Eagles (1973-74)
- Valley Forge (PA) Minutement (1974)
- Washington (PA) Generals (1971)
- Westminster (MD) Chargers (1971)
- Wilkes-Barre (PA) Bullets (1974)
- Wyoming (PA) Giants (1973)
- Bob Gill, with Steve Brainerd and Tod Maher, Minor League Football, 1960-85 (McFarland and Co., 2002), pp84, 99-100
- "Joe Klecko Works for the Jets", The Miami News, November 22, 1978, p3C
- "Bronco Recalls Days He Was Busted", Pittsburgh Post-Gazette, January 13, 1978, p9
- "Corcoran great or 'a bum'", Reading (PA) Eagle, November 5, 1972, p75.
- "Interstate League Survives Defection Of Five Elevens", Baltimore Sun, March 24, 1971, pC2; "Washington Generals Join Forces With New Seaboard Football League", Washington (PA) Observer-Reporter, March 23, 1971, pB-8
- "Add Hartford To Seaboard Grid League", Gettysburg (PA) Times, May 31, 1972, p20
- "Hartford Quits Seaboard Loop", Lewiston (ME) Daily Sun - Nov 23, 1972, p39
- The team was described in 1972 as "a farm team of Montreal of the Canadian Football League", "Ex-Ag signs pro contract, Deseret News (Salt Lake City), August 9, 1973, p2-D
- "Hartford quits Seaboard loop." Associated Press (1972-11-23). Retrieved 2010-12-20.
- "Hartford Gets Grid Franchise", Reading Eagle - May 31, 1972, p58 The Chiefs played an exhibition game against the New York Jets rookies on July 29, 1972, losing 29-3, "Packer Excels at Quarterback As Jets Top L.I. Chiefs, 29-3", New York Times, July 30, 1972, pS-3; ["Rookie QB Fires Jets", Pittsburgh Press, July 30, 1972, pD-8
- Gill, Bob; Brainerd, Steven (2002-11-15) Minor League Football 1960-1985: Standings, Statistics and Rosters Tod Maher McFarland and Company ISBN 978-0786413676