Why did Al Capone go to prison?

Al Capone went to prison several times during his life, but his most well known imprisonment began with his conviction on charges of tax evasion. He was released in 1939 after serving seven years and paying all associated fines and back taxes.

Capone's career in organized crime began after he dropped out of school in the 6th grade. Prohibition created a thriving black market in alcohol distribution in which Capone quickly rose to power. His most notorious act of violence was the St. Valentine's Day Massacre of 1929, in which his gang murdered seven rival gangsters. Capone died in his Florida home due to a stroke and pneumonia in 1947.