What are the motifs in Voyagers to the West by Bernard Bailyn?

One of the aspects of research that this text illustrates well is the limitations of available sources. Historical research is often plagued by incomplete and imperfect data sources as sources are lost over time or simply not recorded. Bailyn centers his research on the Register and uses other sources to highlight the information that it contains. He suggests that although this text is imperfect, it is the best source available in order to study the immigration to the colonies in the years leading up to the Revolution.