Philip Morris and other tobacco companies have been using ammonia in their manufacturing for more than half a century, and for a variety of purposes: to highlight certain flavors, to expand or "puff up" the volume of tobacco, to prepare reconstituted tobacco sheet ("recon"), to denicotinize (reduce the amount of nicotine in) tobacco, and to remove carcinogens. By the early 1960s, however, Philip Morris had also begun using ammonia to "freebase" the nicotine in cigarette smoke, creating low-yield (reduced-tar or -nicotine) cigarettes that still had the nicotine kick necessary to keep customers "satisfied" (i.e., addicted). We show that Philip Morris discovered the virtues of freebasing while analyzing the impact of the ammoniated recon used in Marlboro cigarettes. We also show how Marlboro's commercial success catalyzed efforts by the rest of the tobacco industry to discover its "secret," eventually identified as ammonia technology, and how Philip Morris later exploited the myriad uses of ammonia (e.g., for flavoring and expanding tobacco volume) to defend itself against charges of manipulating the nicotine deliveries of its cigarettes.