Perfect Teams?

These teams not only won every game in their season, but they weren't scored on either...

1901:  Michigan  (11-0)

1911:  Utah State  (5-0)

1917:  Texas A&M  (8-0)

1919:  Texas A&M  (10-0)

1932:  Colgate  (9-0)

1938:  Duke  (9-0)

1939:  Tennessee (10-0)