It was not the imam’s first time at the rodeo.

Scheduled to deliver an invocation at the Fort Worth Stock Show and Rodeo last week, Moujahed Bakhach of the local Islamic Association of Tarrant County canceled his appearance because of the backlash brought on by a prayer he had offered a few days before. The imam had been asked to confer a blessing on horses, riders and members of the military. He was met with gasps from the audience and social media complaints: “Outraged at a Muslim prayer at an all American event!” “Cowboys don’t want it!”

Vocal anti-Islamic sentiment is undergoing a revival. Four days before the imam’s canceled benediction, protesters at the State Capitol in Austin shouted down Muslim speakers, claiming Texas in the name of Jesus alone. In North Carolina two weeks earlier, Duke University’s plan to broadcast a Muslim call to prayer was abandoned amid threats of violence. Meanwhile Gov. Bobby Jindal, Republican of Louisiana claimed that if American Muslims “want to set up their own culture and values, that’s not immigration, that’s really invasion.”

No matter how anxious people may be about Islam, the notion of a Muslim invasion of this majority Christian country has no basis in fact. Moreover, there is an inconvenient footnote to the assertion that Islam is anti-American: Muslims arrived here before the founding of the United States — not just a few, but thousands.

They have been largely overlooked because they were not free to practice their faith. They were not free themselves and so they were for the most part unable to leave records of their beliefs. They left just enough to confirm that Islam in America is not an immigrant religion lately making itself known, but a tradition with deep roots here, despite being among the most suppressed in the nation’s history...