A variety of dangerous illicit drugs have historically loomed large in American society. Some of today’s most notorious substances were once medically endorsed and easily available to the public. When it comes to the development of social attitudes and legal policy toward these drugs, each substance charts a unique path that includes its discovery, use and misuse, influence on our culture, and increasing regulation and antidrug enforcement. We’ve examined the histories of five major substances of abuse and the roles they’ve played in various eras of our society and major cultural moments. Click on the links above to learn more about the extent of the impact of these drugs on our nation.