The latest U.S. Census Bureau American Community Survey reports that 1,301,443 people in the U.S. speak French at home.This includes speakers of French dialects, such as Patois and Cajun, who are over 5 years old. In fact, French is the fifth most common non-English language spoken in U.S. households, after Spanish, Chinese, Vietnamese, and Tagalog.
Francophone communities in the United States have many different historical and geographic origins.Some Francophone communities trace their lineage as far back as the seventeenth and eighteenth centuries, when settlers and refugees immigrated from Europe and Canada. These groups, such as the Acadians of Maine and Louisiana have passed their language down through the generations. Other communities of French speakers arrived in the U.S. more recently, mainly from France, Haiti, Senegal, Côte d’Ivoire, and other African countries.

Source www.frenchculture.org