“Long before today’s anxiety about terror attacks, Spain and England feared that enslaved Africans would be more susceptible to revolt if they were Muslim” writes Andrew Lawler in Smithsonian.com .
As stated in Sylviane A. Diouf’s Servants of Allah: African Muslims Enslaved in the Americas:
“Direct trade [to the Americas] with the African coast was forbidden for fear that with Africans coming straight from Africa, Islam would find its way into the new colonies. … The Crown’s fears were well expressed in a royal order of 1543, which stated that the Muslims should not be introduced to Spain’s American possessions because “in a new land like this one where faith is only recently being sowed, it is necessary not to allow to spread there the sect of Mahomet or any other.” … After the first slave uprising in the New World, led by the Wolof in 1522, a royal decree of May 11, 1526, specifically forbade the introduction of “Gelofes” (Wolof), negros (blacks) from the Levant (or Middle East), those who had been raised with the Moors, and people from Guinea without a special license from the Casa de Contratación, which regulated the slave trade and put levies on the slaves. All the groups that the decree prohibited were either completely or mostly Muslim. Within fifty years, five decrees were passed to forbid the introduction of African Muslims to the Spanish colonies. This insistent reissuing of the prohibition shows that Muslims nevertheless continued to arrive and to cause concerns and problems in the New World. The colonists claimed that the Muslims incited the other nations to rebellion, and it was feared that they would take Islam to the Indians.”
Lawler concludes, “The real threat to peace and security, of course, was the system of slavery itself and a Christianity that countenanced it. The problem wasn’t the faith of the immigrants, but the injustice that they encountered on their arrival in a new land.”