True fact: the US was hardly better at ruling places like the Philippines than the Spanish were. To quote William J. Bryan: "All we did was replace an oppressive Spanish regime with an oppressive American regime."
One may also argue that the U.S. saved the Filipino from being ruled by Imperial Germany or Japan, which arguably may have been worse in the long-run.
As for the most racist election 1864 definitely comes to mind if one wishes to use the modern idea of "racism." Shortly before Christmas, 1863, a 72-page pamphlet appeared for sale on newsstands in New York City. It cost a quarter and was titled
Miscegenation: The Theory of the Blending of the Races, Applied to the American White Man and Negro. The pamphlet sought to interject race into the encroaching Fall Campaign by advising the Republican Party to add a "miscegenation plank" to the platform calling on "mandatory white and Negro unions." The pamphlet, written by
New York World reporter named David Goodman Croly, was cited by Democratic Congressman Samuel S. Cox in a speech blasting the Lincoln Administration social policy towards newly liberated freedmen in occupied territory. In fact, the whole thing was but a hoax that introduced racial issues into an already toxic campaign.
FUN FACT: David Goodman Croly's wife Jane Cunningham Croly was a leading female journalist and feminist who was inducted into the National Women's Hall of Fame in 1994. She helped her husband write the miscegenation pamphlet.