Who were the Ivy League football kings in the 1920s?

1920-Dartmouth (3-0)
1921-Cornell (3-0); Navy (2-0)
1922-Cornell (3-0); Princeton (2-0)
1923-Yale (4-0); Cornell (3-0)
1924-Pennsylvania (2-0)
1925-Dartmouth (3-0); Penn (3-0)
1926-Brown (3-0)
1927-Yale (5-0)
1928-Army (2-0); Navy (2-0)
1929-Dartmouth (4-2)
1930-Army (2-1)