The prominent religion in much of North Africa in the early 1800s was Islam. To arrive at this answer, one could consider the historical context of the region during that time period. The spread of Islam across North Africa had begun in the 7th century through the Arab conquests, and by the early 1800s, Islam had firmly established itself as the dominant religion in the region. Islam had a profound impact on the culture, society, and governance of North African countries, with significant Islamic influence evident in various aspects of life such as architecture, education, and legal systems. Furthermore, historical events, such as the rise of the Ottoman Empire, which held sway over parts of North Africa during this period, also contributed to the prominence of Islam in the region.
The main religion in North Africa hasn't changed since the 600s, so that includes the 1800s and today.
