I never smoked crack. I did live in New York City in the 1980s and 1990s at the height of the crack era. Until my wife and I discovered it, our little boy had an impressive rainbow-colored collection of crack vial caps. Less than three blocks from our apartment, two rival crews sold thousands of rocks everyday. Crack users binged in our unlocked building vestibule. Anything not locked down in our neighborhood was stolen. At the time, I was horrified.A bit over a decade later, living now at the ragged edge of Center City Philadelphia, a small crack crew operated in the alley below my living room window. By the time I lived in Philly, beginning in 2004, crack had largely lost its massive appeal. Other drugs, including meth, opioids, and potent strains of cannabis, had replaced it. But my crack-dealing neighbors had found a market niche—the men who congregated near a homeless shelter a few hundred feet from my building.I got to know the crew’s head of operations. He was a civil and fascinating man (when he was not too high on the blunts that he smoked endlessly). Our conversations planted a seed and, eventually, I chose to write this history of the crack cocaine years in the United States.I saw a history of crack as a way to think about how drug regimes have figured American life. Though the story does not usually get into our history textbooks, American life has been fundamentally shaped by our collective desire to use and regulate narcotics and other intoxicants that affect our state-of-mind. For nearly fifty years, in an unprecedented way, we have waged a “war on drugs” that has profoundly altered the lives of the American people.In the 1980s and 1990s, crack cocaine was in the crosshairs of that drug war. As a small population became dangerously addicted to crack, tens of millions more decided that crack cocaine was a terrifying danger and unleashed a punishing regime that has rarely been matched in American history. Dealers, even those who were caught selling less than a paper clip’s weight, had their lives destroyed. Rather than treat the lure of crack cocaine as a public health crisis, Americans responded to crack use by locking up tens of thousands of crack dealers, who were disproportionately poor African American men. A history of the crack years, I believe, tells us a great deal about race, class, economic opportunity, and the contested nature of mercy and justice in the United States.