That may be no surprise, since a quarter of the estimated 6 million Muslims in the United States are converts.
Delia Gallagher looks at two people who chose that path.
Alison Poole says this phrase three times in Arabic, and then in English.
There is no God. But God. And I bear witness. And I bear witness. That Muhammad. That Muhammad. Is the messenger of God. Is the messenger of God. And her conversion ceremony is complete. She's now a Muslim. Moments later, she'll marry Sammy and become Alison El Gamal. But Alison, who was raised a Southern Baptist in North Carolina, says faith, not marriage, made her want to become a Muslim.
I think for a long time, I've been looking for something. There's been like a peace missing. Always one little thing that maybe wasn't right.
At a ceremony marking the Muslim holy month of Ramadan, she explained why Islam appeals to her.
I think because it's much more about peace. I'm praying five times a day. It's kind of hard to go out and say bad things or do bad things when you're praying five times a day.
The imam who married Alison says he's seen more American converts recently, in part because of the prominence of Islam in the news.
It may sound paradoxical, but what happens is that when something becomes more in the news, people tend to want to know about it.
Alison says she was already on a spiritual quest when she began to hear a lot about Islam post 9-11.
Barbara Cardibuke, another recent Muslim convert, says 9-11 also played a part in her conversion.
After 9-11, I thought this is the time when people really have to start looking for real answers to get away from everybody fighting back and war.
You have to start looking towards God.
Barbara says through Islam, she found a one-on-one relationship with God she was unable to find as a Roman Catholic.
I always felt when you go to church, you're praying to Jesus or you're doing Hail Marys.
You know, I used to think, well, where's God?
She says her family has been mostly supportive of her conversion.
Alison says her family is completely behind her decision.
It's a choice she's proud of and says she'll keep for life.
Delia Gallagher, CNN, New York.