The official census point towards a figure between six to seven million, which I think, is downplayed. Apart from the local American reverts and the Afro-American Muslims which account for a fairly large amount of Muslims, many Muslims hail from the Indian Subcontinent, Bangladesh, the Middle Eastern Countries, and many African countries, particularly Somaila and Ethiopia. Much is heard of Elijah Mohammed and his group. The Nation of Islam of Islam which was founded by Elijah Mahomed was more a political party, and it's Islamic outlook was severely flawed. As the Imam of your precinct, describe in an impersonal way, the experience of your congregation living and practicing Islam.
Life is generally very hectic in America.
This leaves very little, if not time for religion and their families. Many Muslims have prospered immensely in the USA, but many come to the USA to work leaving their families in their countries of origin. By living frugally, they manage to send the bulk of their earnings home. Whilst this is not objectionable, many social evils are bred in this way. Besides, such people are too involved in their jobs to pay special attention to Islam.