The War on Drugs and the rise of private prisons are inseparable. As incarceration became a for-profit business, they needed more people in jail to increase revenue. The War on Drugs provided the perfect excuse to lock people away for years on minor offenses.
Millions of people have been imprisoned during The War on Drugs since the 1970s, and even today police continue to arrest an estimated 1 million people on drug-related charges every year. Over half of those arrests are for cannabis charges.