The 18th Amendment, establishing prohibition of alcohol sales also was heavily linked to the 16th Amendment, establishing an income tax.\n\nThe 16th was ratified in 1913. The 18th followed it in 1919. Prior to the 16th, most federal and state revenue came from tariffs instead of taxes. Often the biggest source of tariff income was from liquor sales. Only after the 16th Amendment allowed a new revenue source could liquor sales be prohibited.