One of the great things about atheism is its decentralized nature, we're all free to believe whatever we want - we're not bound to any sacred book, any dogma, or any particular leader. But it also makes it tough to agree on anything besides the basic fact that we all don't believe in gods. There's a reason why attempts to organize atheists are referred to as "herding cats".
And the disorganization has been very helpful in the past, when being outed as an atheist usually meant a cruel and unjust death. In medieval times, any centralized organization anathema to the church would quickly be destroyed by wrathful zealots, as pagan religions were demolished. Atheism survived in no small part due to its invisible nature. Religious doubt throughout world history has been like a hydra: you can lop off one head, but it survives - cities, even whole countries, can be firmly pressed into orthodoxy, and doubt can be discouraged in the cruelest and most barbaric ways, but all it ultimately does is drive doubt into secrecy there (where it inevitably outlasts its aggressors) while it prospers in freer societies elsewhere.
But that disorganization is also a huge handicap right now, because it means that atheists in America have very little political influence (to the point that it's commonplace for politicians to attempt to out-Jesus each other each election cycle and news shows can host "discussions" on atheism sans any actual atheists and say that atheists should sit down and shut up) and don't have a whole lot in the way of social support for other atheists (being a lone atheist is really tough, especially in the Bible Belt).
We need a community. We also need to get together and fight for what we believe in.