Final answer:
Prohibition in the United States led to increased smuggling and the rise of organized crime figures like Al Capone, who profited immensely from the illegal alcohol trade, especially through bootlegging and smuggling across the Detroit River.
Step-by-step explanation:
The legal change in Canada that led to the increase in smuggling into the United States and profited criminals like Al Capone was Prohibition. Prohibition was a nationwide constitutional ban on the production, importation, transportation, and sale of alcoholic beverages in the United States from 1920 to 1933. During Prohibition, organized crime figures such as Capone capitalized on the public's desire for alcohol by engaging in bootlegging, which is the illegal production and distribution of liquor. As a result, smuggling activities across the border, especially via the Detroit River, increased dramatically.
In addition to bootlegging, Capone's criminal organization, known as the Chicago Outfit, participated in a multitude of illegal operations, generating vast amounts of revenue. However, it was ultimately tax evasion that led to Capone's imprisonment, drawing attention to the difficulties law enforcement faced in tackling organized crime head-on during that era. Despite the intentions of the 18th Amendment, Prohibition not only failed to curb alcohol consumption but also intensified the power and reach of organized crime.