Findings:

• National Puzzlers' League
• National Hockey League
• National League
• National Football League
• National Negro Business League
• British National League
• National Sunday League
• National Civic League
• National League Division Series
• National League Championship Series
• National Forensic League
• National Women's Football League
• National Relay Ball League
• National Rugby League
• National League Rookie of the Year
• National Fascist League
• Federal Baseball Club of Baltimore v. National League of Professional Baseball Clubs
• National League of Cities v. Usery
• National League Most Valuable Player
• 1898 National League Special Instructions to Players
• National Hockey League Players' Association
• National Book League
• Michael Bolton singing the National Anthem in Game 4 of the 2003 American League Championship Series
• minor league
• Major League Baseball
• Ivy League
• English Premier League
• Champions League
• Football League
• League Cup
• Human League
• The League of Extraordinary Gentlemen
• Rugby League
• A League of Their Own
• The League of Gentlemen
• League of Nations
• Canadian Football League
• American League
• league
• Justice League of America
• Major League
• Dead Sports Leagues
• American Football League
• 20,000 Leagues Under the Sea
• Lucy Stone League
• Delian League
• League For Programming Freedom
• Texas League single
• Major League Baseball memories
• Alaska League Baseball
• The Red-headed League
• Atlantic League
• League of Non-Aligned Worlds
• East Coast Hockey League
• Puzzler (e2poll)
• Catholic League
• Carolina League
• International League
• Pacific Coast League
• Southern League
• Eastern League
• World League of American Football
• Texas League
• The League Against Tedium
• California League
• National Baseball Hall of Fame and Museum
• Anti-Defamation League
• War Resisters League
• Casting the League of Extraordinary Gentlemen today
• Justice League: A Midsummer's Nightmare #1
• Justice League: A Midsummer's Nightmare #2
• Justice League: A Midsummer's Nightmare #3
• South Atlantic League
• Australian Football League
• Victorian Football League
• Pet Aid League
• Patriot League
• League Coordinator
• KDE League
• Peloponnesian League
• Central League
• Pacific League
• 20,000 Leagues Under the Sea: Introduction
• The Cyberathlete Professional League
• Superhero League of Hoboken
• Spartacist League
• 20,000 Leagues Under the Sea: Units of Measure
• 20,000 Leagues Under the Sea: 1: A Runaway Reef
• Correspondence Chess League of America
• Little League
• Junior League
• League of Uri
• Hanseatic League
• La Leche League International
• Ultimate Frisbee Fantasy League
• The League of Schmalkalden
• Minibike Jousting League
• Big League Chew
• Mutant League Football
• Major League Lacrosse
• bush league
• Negro Leagues
• University Interscholastic League
• 20,000 Leagues Under the Sea: 2: The Pros and Cons
• 20,000 Leagues Under the Sea: 3: As Master Wishes
• 20,000 Leagues Under the Sea: 4: Ned Land
• 20,000 Leagues Under the Sea: 5: At Random!
• 20,000 Leagues Under the Sea: 6: At Full Steam
• 20,000 Leagues Under the Sea: 7: A Whale of Unknown Species
• Florida State League
• Midwest League
• New York-Penn League
• Youth Communist League
• Junior Classical League
• Just-Us League of Super-Toons
• Northwest League
• Little League World Series
• Minor League Baseball
• Appalachian League
• Land League
• The League of Women Voters
• Major League Baseball Rulebook
• League of Armed Neutrality
• American League Division Series
• American League Championship Series
• Lightning League
• Lightning League Vehicles
• La Leche League Leader
• Smart enough to get into the Ivy League, not good enough to go to Stanford
• League for the Emancipation of Labour
• War of the League of Augsburg
• Nationwide League
• League of Arab States
• Arab League
• Milton Keynes Table Tennis League
• Holy League
• League of Venice
• All-American Girls Professional Baseball League
• Pokemon Puzzle League
• Welsh Premier League
• American Municipal League
• Muslim League
• West Australian Sunday Football League
• Scottish Premier League
• 2002 World Series
• Champions League: 1955-56
• 20,000 Leagues Under the Sea: 8: "Mobilis In Mobili"
• 20,000 Leagues Under the Sea: 9: The Tantrums Of Ned Land
• 20,000 Leagues Under the Sea: 10: The Man of The Waters
• 20,000 Leagues Under the Sea: 11: The Nautilus
• 20,000 Leagues Under the Sea: 12: Everything through Electricity
• 20,000 Leagues Under the Sea: 13: Some Figures
• 20,000 Leagues Under the Sea: 14: The Black Current
• 20,000 Leagues Under the Sea: 15: An Invitation in Writing
• 20,000 Leagues Under the Sea: 16: Strolling the Plains
• 20,000 Leagues Under the Sea: 18: Four Thousand Leagues Under the Pacific
• 20,000 Leagues Under the Sea: 19: Vanikoro
• 20,000 Leagues Under the Sea: 20: The Torres Strait
• 20,000 Leagues Under the Sea: 21: Some Days Ashore
• 20,000 Leagues Under the Sea: 22: The Lightning Bolts of Captain Nemo
• 20,000 Leagues Under the Sea: 23: "Aegri Somnia"
• 20,000 Leagues Under the Sea: 24: The Coral Realm
• Jewish Defense League
• American League Rookie of the Year
• Beer league
• American League Most Valuable Player
• Major League Baseball Teams
• Federal League
• New England League
• American Regions Mathematics League
• Major League Baseball Players Association
• First Lego League
• Major League Soccer
• Amphictyonic League
• Progressive Voters League
• Commissioner of Major League Baseball
• Major League Baseball and The Puerto Rico Experiment
• Anti Nazi League
• Virginia League
• Columbian League
• Players' League
• Justice League of Amazons
• Arcade League
• Major League Baseball's "permanently ineligible" list
• Russian Super League
• American Computer Science League
• International Marching League
• Virtual League Baseball
• Fantasy Powers League

If you Log in you could create a "National Puzzlers League" node. If you don't already have an account, you can register here.