As Baha'is say, there is only one race the human race. But culturally people are so very different. Like a lot of the integrating into the American culture wasn't necessarily something that was all that positive. We have the break down of the family, a very materialistic and consumeristic society, and a very strongly independent attitude... which leans toward not trusting others. And others are anyone who is not like us. And can be anybody. Right now lots of Americans don't trust Middle-Easterners, socialists, definitely not communists, and unfortunately, these past couple of years, some Americans still consider some dark-skinned people as "others" and don't want them here. And that ties in with what people have done to the Jews.
These are all consequences of globalisation and modernity. Consider the accelerating changes that have taken place since the nineteenth century.
1/ Human's are living longer with much better health.
2/ Levels of education have dramatically increased with basic education universally established.
3/ Levels of prosperity overall have increased dramatically.
4/ The means of communicating with people across the globe have improved dramatically.
5/ Travel and migration have increased.
So we have the opportunity to have much more contact with people from different cultures, races and religions if that's what we want. With materialism we do have access to technologies that have greatly improved the quality of our lives. With these changes we are much greater awareness of poverty, inequality, racism and religious prejudice.
Urgent needs for humanity include establishing better means of cooperating to manage the environment and shared resources, seeing ourselves as one people. Obviously there is an increase in the forces that would divide us including nationalism, racism and extreme political ideologies.
The best means to ensure we are on the right side of history is to become aligned with communities and organisations that are genuinely promoting the values and skills needed to negotiate the challenges of our modern world.