I found that many Americans have families with Africans. Why don’t they mind if their wives have such dark skin?

Who says there is no racial discrimination in the United States? Some parts of the United States still have white supremacy and treat other people of color as second-class citizens. It's just that some white people want to be different, so they find some people of color to be their spouses. Nothing is absolute and cannot be generalized. China is different from the United States. The United States is a country of immigrants, so there is a hodgepodge of different races. If you want to live in harmony, you must learn to tolerate and tolerate each other. This is caused by the social environment.

I once met a Chinese man from Beijing who came to the United States for shopping and tourism. He took his fiancée with him, and his fiancée was a black American. Therefore, discrimination against black people in China is not absolute.

I hope the above will be helpful to you.