In the 1700's, the yakuza began organizing into families, and group members united with each other for mutual protection. They began to control booths at fairs and markets and developed a reputation for shoddy merchandise and deceptive salesmanship. They also played a role in Japan's gambling tradition. In the 1800's, the yakuza began to modernize, recruited members from construction and dock jobs, and even began to control the rickshaw business. Group members became involved in politics, taking sides with certain politicians and officials. They cooperated with the government so they could get official sanction or at least some freedom from the government. In the 1900's, American occupation forces in postwar Japan saw the yakuza as a primary threat to their work and realized they were well-organized and operated with support from some government officials. Between 1958 and 1963, the number of group members rose by more than 150 percent to 184,000. Approximately 5,200 yakuza gangs operating throughout Japan began to stake out their territories and violent gang wars occurred. These gangs controlled many businesses, engaged in sophisticated gambling and loan sharking activities, and invested heavily in sports and other entertainment. They also became involved in drugs, money lending, smuggling, and pornography. The structure of the yakuza is described, and the involvement of the yakuza in business and politics in contemporary Japan is discussed.