Mapping Slavery in Detroit is a University of Michigan Undergraduate Research Opportunity Program (UROP) project to develop and explore the history of slavery in Detroit and its effect on the modern-day city.
The project's web site explains "the existence of slavery in the city of Detroit and its surrounding areas is a topic that has yet to be thoroughly researched and explained. In fact, current public portrayals of Detroit’s history still emphasize the role of the Underground Railroad. The primary goal of this project is to provide a more complete picture of slavery in the Detroit area for the general public, students, and scholars in order to acknowledge the full history of the area and to learn from it."
The web site contains not only a lot of text about slavery in Detroit, but also has an interactive map and a number of graphs that illustrate the history of Detroit.
You can learn more about the project at http://mappingdetroitslavery.com.