Important work on slavery has continued; for instance, in 2003 Steven Hahn published the Pulitzer Prize-winning account, "A Nation under Our Feet: Black Political Struggles in the Rural South from Slavery to the Great Migration", which examined how slaves built community and political understanding while enslaved, so they quickly began to form new associations and institutions when emancipated, including black churches separate from white control. In 2010, Robert E. Wright published a model that explains why slavery was more prevalent in some areas than others (e.g. southern than northern Delaware) and why some firms (individuals, corporations, plantation owners) chose slave labor while others used wage, indentured, or family labor instead.