Walter Johnson's Soul by Soul is a well-researched and well-documented history of slaves encumbered within the "peculiar institution" of slavery in the South in Louisiana. His thesis shows the human face of slaves and thoroughly discounts the South's rationalizing theories of African slaves as inferior creatures incapable of fending for themselves and therefore needing looking after. Johnson chronicles the daily experiences and the extensive effective communication networks of the people who were sold into slavery as recorded in legal papers, diaries, letters and bills of sale, and other documents.

As well as showing the detailed daily operation of slave trade and slave life, Johnson shows that slaves had interpersonal relationships with their owners--and even to some extent with the slave traders who would coach the slaves on how to present themselves--and could at times influence to whom they were sold or resold, their return to the salve trader under redhibition laws ("picked a lemon" laws), and sometimes even forestall the break up of their families. In this way Johnson presents and proves a thesis that debunks the theories of slaves as non-human or sub-human creatures, and therewith raises American slavery up from being a meaningless abstraction that is irrelevant today by showing the contrary: slavery defines national characteristics and has an influence even today.