America is not unjust, racist, or sexist. While we are not a perfect society, and there are these elements, women and minorities have gone on to great success. The United States just had a woman as the presidential nominee of a major political party. This would not happen in an unjust, racist, sexist society.
America is not perfect, but what place in world is? In the history of the world, what civilization has ever been perfect. Yes, America has problems. However, America is not unjust, racist and sexist. America is still the land of opportunity. When a wrong has been committed, Americans work to correct that injustice.
I think if we take people as individuals, then generally they are not unjust, racist or sexist. There are horrible people everywhere but they are not the majority here. I think the internet and it's anonymity brings out the mob mentality in everyone and this is why America appears so terrible and polarized right now.
Although, no country is perfect and there are improvements to be made in terms of America's justice system, as well as treatment of women and minorities, it is unfair to say that America, as an entire country, is unjust, sexist, and racist. Currently, the American president is an African American male and equal rights acts and affirmative action have recently benefited many women and minorities in this country. There is more opportunities for previously marginalized people in America than ever before.