Mother of Rivers = Mississippi
Mother of Rivers (not a typo; there are two) = Missouri
Home of Tax Free Shopping = New Hampshire
Mother of Presidents = Virginia
Mother of Modern Presidents = Texas
Land of Infinite Variety = New Mexico
Hog and Hominy State = Iowa
Tomato State = California
Baja Wisconsin = Michigan
Rip Van Winkle State = New York
Holland of America = New York
Switzerland of America = Colorado
Land of the Noonday Moon = Alaska
Potatonia = Idaho
Hemp State = Oregon
Home of Beautiful Women = California
Puke State = Texas
Blue Law State = Pennsylvania

Ranging from wild to educated guesses.