Jean Baptiste Mathurin, the Hausa and Haiti

Jean Baptiste Maturin appears in 1801, when he married Anne Ogé, on folio 49 of the ANOM's digitized archive of the état civil. 

To give a real example of how some Haitians have minor Hausa or northern Nigerian ancestry, the example of Jean Baptiste Maturin is enlightening. To determine this Hausa connection, one must consult the parish registers of Saint Domingue from those "exciting" years between emancipation and Haitian independence. Many ex-slave cultivateurs appear in these registries as free people, getting married or registering the births of their children. If one is lucky, one might find an ancestor who had been formerly enslaved and, occasionally, details about their African or Creole background. 

In this example, we see in the 1801 parish register for Jacmel that Jean Baptiste Mathurin married Anne Oge, a Creole who was born in Jacmel. Jean Baptiste Mathurin, however, was a native of the "Hausa country in Africa" and therefore, obviously not native to Jacmel. As a Hausa, a minority among the African "nations" and with extremely skewed gender ratios, it was no surprise he married a Creole woman. This would explain why some Haitians do indeed descend from Africans of diverse regions, but it may only present itself in genetic testing at trace amounts. 

Family Search's website is precious for finding documents. Here is digitized the 1853 marriage record of Jean Philippe Mathurin. 

Unsurprisingly, Mathurin and wife Anne Oge had at least 2 children, Jean-Philippe Mathurin. Indeed, Jean Philippe was named as a child of Jean Baptiste in 1801, born before he married Anne. Apparently he had a brother, Edouard. Jean Philippe was around 16 years old when his parents married, probably because they were free and it was easier to do that and have stable family structures. Jean-Philippe Mathurin himself would have 5 children with Marie Louise Jacques, before marrying her in 1853. One can verify that Jean-Philippe Mathurin was indeed the child of Jean Baptiste Mathurin and Anne Oge because his marriage certificate lists his place of birth as Gosseline, the very same area Jean-Baptiste Mathurin and Anne Oge were living in back in 1801. 

The above example serves to show how "Hausa" ancestry could be inherited by Haitians in small amounts. Perhaps most, like Jean Baptiste Mathurin, ended up in relationships with non-Hausa women and were rather quickly largely absorbed into the Creole population. In areas like Jacmel, the slave population was already substantially Creole by the late 1700s, and outside of perhaps a few extreme cases, it was not likely for Muslim Hausa to have found communities of fellow believers to build a community with, as happened in Trinidad or even among the Fulanis encountered by Descourtilz in Saint-Domingue.