While this site is supposed to be about the Church in DC, relative to the size of the Atlantic Ocean, we in the DC area are quite close to New York City, and have experienced some of the same demographic and spiritual trends.
So you may find this book of interest: Word Made Global: Stories of African Christianity in New York City. Mark Gornik's study of NYC African Christianity won the Christianity Today book award for the category of Missions & Global Affairs.
Product Description from Christianbook.com:
"In a groundbreaking and engaging work of ethnography, urban studies, and theology, Mark Gornik explores the recent development of African Christianity in New York CIty. Through the lens of three African immigrant church bodies - the Church of the Lord (Aladura), the Presbyterian Church of Ghana, and the Redeemed Christian Church of God - this book examines the pastoral, spiritual, and missional dynamics of this global and transnational movement.
"Word Made Global: Stories of African Christianity in New York City draws on ten years of involvement and research, during which Gornik conducted more than one hundred interviews and attended several hundred worship services, Bible studies, prayer meetings, healing services, seminars, community meals, harvest festivals and other events at more than 35 churches throughout New York City."