François G. Richard posits that: The Kingdom of Sine remained a modest participant in the Atlantic system, secondary to the larger Wolof, Halpulaar [speakers of the Pulaar language i.e. the Fula and Toucouleur people] or Mandinka polities surrounding it on all sides... As practices of enslavement intensified among other ethnic groups during the 18th century, fueling a lucrative commerce in captives and the rise of internal slavery, the Siin may have been demoted to the rank of second player, in so far as the kingdom was never a major supplier of captives.In his 1968 publication: Islam and Imperialism in Senegal: Sine-Saloum, 1947-1914, Professor Martin A. Klein notes that, although slavery had existed in Wolof and Serer culture, as well that of their neighbors, the institution of slavery did not exist among the Serer Noon, Serer N'Diéghem, and the Jola people, "who had egalitarian social structures and simple political institutions.

"[7] Klein also notes that: "In times of peace, the Kingdom of Siin more readily supplied grain, cattle and other basic necessities to the French."

[8] Conflicts erupted with the Muslims to the north, as when Marabout Nasr al Din attacked Mauritania and the Wolof across the border in 1673, but he was defeated through an alliance between local forces and the French.

[5] During the Napoleonic Wars, Great Britain captured Gorée in 1803 and Saint-Louis in 1809, and proclaimed the abolition of the slave trade in 1807, to which the French had to agree upon recovering the two posts.

In 1859, the Serers of Sine, led by their king - Maad a Sinig Kumba Ndoffene Famak Joof launched an attack against the French and their ally forces, resulting in the Battle of Logandème.

By 1860, the forts built between Médine and St. Louis allowed Faidherbe to launch missions against the Trarza Moors in Waalo (north of the Senegal river), who had previously collected taxes on goods coming to Saint-Louis from the interior.

Faidherbe also started the westernization of the area by developing banks, civil administration, and also established an accord with Senegal's religion, Islam.