The cheaply printed ephemeral collections of songs put out by the minstrel troupes themselves were as important as the performances themselves to the spread of the songs and their entry into the folk process.
As I understand it, your motive in starting this thread and others on different aspects of African-American music and its history and influence is to end up with a series of "mini-essays" that can accompany and explain the songs, both spiritual and secular. Faigin's article is a convenient starting point for one important stage. Comments and suggestions will lead to the "momentarily definitive" essay that can be preserved in Mudcat. At least that is my take on your intent.