George Carlin's Muhammad Ali/America the Beautiful routine ends with him singing:
O beautiful for smoggy skies
For strip-minded mountains majesty
Above the asphalt plain
Men sheds his waste on thee
And hides the pines with billboard signs
From sea to oily sea.
When Carlin reused this routine in his 1972 album Class Clown, he added a piece on "the sexual side of Vietnam."