Islam is the third largest religion in the United States after Christianity and Judaism. According to a 2010 study, it is followed by 0.9% of the population, compared with 70.6% who follow Christianity, 22.8% unaffiliated, 1.9% Judaism, 0.7% Buddhism, and 0.7% Hinduism. According to a newer estimate done in 2016, there were 3.3 million Muslims living in the United States, about 1% of the total U.S. population.
American Muslims come from various backgrounds and, according to a 2009 Gallup poll, are one of the most racially diverse religious groups in the United States. Native-born American Muslims are mainly African Americans who make up about a quarter of the total Muslim population. Many of these have converted to Islam during the last seventy years. Conversion to Islam in large urban areas has also contributed to its growth over the years.
While an estimated 10 to 30 percent of the slaves brought to colonial America from Africa arrived as Muslims, Islam was stringently suppressed on plantations. Prior to the late 19th century, most documented non-enslaved Muslims in North America were merchants, travelers, and sailors.
From the 1880s to 1914, several thousand Muslims immigrated to the United States from the former territories of the Ottoman Empire and the former Mughal Empire. The Muslim population of the U.S. increased dramatically in the 20th century, with much of the growth driven by a comparatively high birth rate and immigrant communities of mainly Arab and South Asian descent. About 72% of American Muslims are immigrants or "second generation".
In 2005, more people from Muslim-majority countries became legal permanent United States residents—nearly 96,000—than there had been in any other year in the previous two decades. In 2009, more than 115,000 Muslims became legal residents of the United States.
One of the earliest accounts of Islam's possible presence in North America dates to 1528, when a Moroccan slave, called Estevanico, was shipwrecked near present-day Galveston, Texas. He and four survivors subsequently traveled through much of the American southwest and the Mexican interior before reaching Mexico City.