Prisoners in the US are part of a hidden workforce linked to hundreds of popular food brands

A hidden path to America’s dinner tables begins here, at an unlikely source – a former Southern slave plantation that is now the country’s largest maximum-security prison.

Unmarked trucks packed with prison-raised cattle roll out of the Louisiana State Penitentiary, where men are sentenced to hard labor and forced to work, for pennies an hour or sometimes nothing at all. After rumbling down a country road to an auction house, the cows are bought by a local rancher and then followed by The Associated Press another 600 miles to a...