A lot of it is tribal. People aren't comfortable outside of their community of like minded individuals, and disdain those who think differently. This sort of tribal community can be defined by different things: some examples are geography, occupation, social status, race, and of course religion. Each comes with a set of things taken on faith. Separating from the tribal mindset requires independent thought. People don't like to think, because thinking is work, and work is unpopular. Breaking from your tribe takes effort that a lot of folks just don't want to exert.

I think we are making progress, I worked three southern bible belt guy's this past year and to my surprise they were all atheist, we got along great and had a blast talking abought the lies of christianity. Maybe with the help of the internet, in a thousand more years it won't even exist.

Your idea that the US is "the land of the free" is inaccurate. We have the highest incarceration rate. We have 25% of the world's prisoners while having only 5% of the people. Our laws concerning alcohol and other intoxicants are prudish. Our celebrated bill of rights is dead. Freedom of speech is a joke when protesters are met with police violence. Police, by the way, that that are militarized more than any in the world and have killed on averse three citizens a day for the past four years.

Yeah land of the free. Whoever told you that was your enemy.

My view is that so few people had ever met an atheist/agnostic. We were a very religious nation for a long time and people started associating anything bad with not having god. Eventually this led to prejudices grounded on nothing. It's getting better now. Slowly, but I'm not afraid to mention I'm atheist to most people in bible belt Texas. Progress just takes time.

There is a big difference in the ideals of a nation and it's people.

I would say it wasn't discrimination so much as being ignored. And probably because there isn't enough of a voting block who isn't denominational.

The believers are deathly afraid of those who don't share their delusions.
Rational thought is a threat to them. It's easier to diminish and discriminate against
anyone whose views are different from their own, than it is to even consider the possibility
that their beliefs are false, and they've been believing in something that has never existed.