Why is 11am on Sunday the most segregated hour in America?

Because people filter religion throught their cultural preferences. Many think God only likes their style of music, or their style of worship. I attend a multiracial church that made diversity one of it's founding principles, and I've seen a lot of people walk in and never come back because they have to endure something that is not their exact style or culture. Churches have to be purposeful in fostering diversity, it just doesn't happen magically. My churches pastor is white, our congregation is roughly 50% black, 40% white, and 10% other. We have over 75 nations represented. We incorporate different styles of music and frequently encourage befriending people of different races. It is human nature to connect with people like ourselves, so you have to be purposeful. Fact is, churches would lose some people if they tried to incorporate this idea, people from all races might feel uncomfortable as soon as something they're not familiar with is presented. If I walked into an all black church, I would feel uncomfortable and a black or hispanic person can think the same thing walking into an all white church. So they go to a church with people who look and worship like they prefer to. It's just basic human nature, but if you want to grow as a Christian, you need to realize God wants us to see past appearances and cultural biases.

Most churches are community based. If a community is primarily of one race or ethnicity then that will be reflected in the church. Mega-churches that attract people from all over a city will tend to be more integrated.

In my experience, minorities prefer minority churches. When they attend integrated churches their minority status is more evident to them. If a given state is 2% Asian and an Asian attends an integrated church with a congregation of 500 people, there will only be 10 Asians in a fully integrated church. For a black person there would only be about 60 blacks (12% US population) in the same church. That's not segregation, that's math. That's why most minorities prefer to attend a minority church.

no they are not maybe where you are but all of the churches i have seen and i have seen a lot are very multi racial

don't know but I guess people feel more at home with their friends and family, usually you go to a church were your family go's or friends.