Fuelled by tough-on-crime, law-and-order, war-on-drugs policies (Nixon, Reagan, ...), the USA have developed into the world's undisputed leader in imprisonment, with African Americans being disproportionally affected (also by the "superpredator" myth).
The song "Letter to the free" (2016) by Chicago-based rapper Common protests this maldevelopment (full of historical references and filmed in an empty prison).