Has an NFL team ever went undefeated?

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Tags

1. #championship
2. #opening
3. #washington
4. #super
5. #through
6. #regular
7. #including
8. #remains
9. #entire
10. #complete
11. #dolphins
12. #season
13. #untied
14. #redskins
15. #finish
16. #undefeated
17. #against
18. #games
19. #three