Entitlement slavery

I would like to read an intellectual history of how exactly “slavery was a boon to economic development” became the leftist position, and “actually, slavery is a retrograde anti-growth system as well as an immoral one” (Marx’s view!) became the neoliberal sellout view.

Matthew Yglesias doesn't need a history book.  

Today we import brown people today as entitlement slaves.  Completely racist, a deceptive labor contract and Yglesias is an advocate, a supporter of race slavery.