A predominantly African-centered TL with a POD in the 1840s, written by Jonathan Edelstein.

What if… the Male Revolt of OTL had a somewhat different outcome ?

“The First Sokoto Republic was a short-lived state that existed in the Sahel during the middle 19th century, chiefly among the Fulani and Hausa. Founded in 1840 by an army of Malê who had been deported from Brazil, in what is sometimes called the “Jacobin jihad,” the Republic occupied the western half of the pre-existing Sokoto Caliphate as well as several of the surrounding emirates. It is frequently compared to other “freedmen's republics” such as Liberia, Sierra Leone and Gabon, but was established by the freedmen themselves rather than an outside agency; the closer comparison to its founding may be the contemporaneous Great Trek of the Afrikaners. Unlike the Boer republics, however, the First Sokoto Republic was an explicitly ideological state, with its charismatic leader attempting to combine Islam with the radicalism of the French and Haitian revolutions. Although the Republic lasted little more than a decade, it was to have a profound social, religious and military legacy…”

To quote Jon himself :

“In OTL, the Malê revolt was defeated in a day, and many Muslim slaves were deported to West Africa afterward. There are still recognizable remnants of Afro-Brazilian culture in Togo and Benin, and a number of prominent families in those countries have Brazilian ancestry. At least one scholar who has studied the Afro-Brazilians has speculated that, if they'd had sufficient time and colonial authorities hadn't interfered, they might eventually have formed a coherent state. In the ATL, the Malê are deported to Africa as a relatively intact force, and they have a leader who's both charismatic and radical. The country they're conquering has about half a century before Europeans come knocking on the door. Any attempt to re-create the French Revolution (even an Islamized French Revolution) in the Sahel emirates is, of course, doomed, but some of the ideas being introduced will stay for the long haul.”

You can read the TL here.