From the Document: "Successive U.S. Administrations have viewed the U.S.-Nigeria relationship as one of the most important in Africa, given Nigeria's size, political role, and economic weight in the region. It is Africa's largest economy and most populous country, with Muslims and Christians constituting nearly equal shares of the population. Nigeria has one of the world's largest Muslim communities and Lagos, Nigeria's commercial center, is among the world's largest cities. In the United States, Nigerians represent the largest African diaspora group."
CRS In Focus, IF10174
Congressional Research Service: https://crsreports.congress.gov/