Final answer:
The Cosa Nostra's entry into the US and Canada led to the rise of organized crime during the prohibition era, with criminal gangs controlling illegal activities like alcohol smuggling and distribution. This resulted in increased violence and corruption.
Step-by-step explanation:
When the Cosa Nostra stepped into the US and Canada, it contributed to the rise of organized crime during the prohibition era. In cities like Detroit and Chicago, illegal activities such as smuggling and distribution of alcohol were controlled by criminal gangs like the Purple Gang and Al Capone's Chicago Outfit. The illegal alcohol trade fueled violence and crime, leading to a breakdown of order. Prohibition also created an environment of corruption, with local police and officials often being on the payroll of the organized crime groups.