Most Americans now live in states where recreational marijuana is legal. Medical marijuana is even more widespread. This special issue of TIME looks at every aspect of this new and evolving world. It examines what we know—and still don't know—about the health benefits of cannabis and its ability to treat PTSD, help with digestive maladies, improve sleep, and ease chronic pain. It considers the law, the business, and the culture of cannabis. At a time when Seth Rogen, Snoop Dogg, and other stars peddle their own lines of weed, what does it mean to be a stoner? How exactly do marijuana dispensaries work? This special edition examines from every angle the question of cannabis's place in and impact on America.