The 21st Amendment, ratified in 1933 to end national Prohibition, gave each state authority to regulate alcohol sales, distribution, and consumption according to local preferences. This state-based system produced the three-tier distribution model now used nationwide, which separates manufacturers (brewers and wineries), wholesalers (distributors), and retailers into distinct, regulated tiers. No single entity can participate in more than one tier under most state laws, preventing monopolistic ''tied houses'' where manufacturers control retail outlets. Each tier operates under separate licensing requirements and regulatory oversight. The system generates tens of billions in annual tax revenue for federal, state, and local governments while ensuring orderly markets and safe products for consumers. States enforce widely varying rules: some operate as control states running their own liquor stores, others allow private retail, and regulatory details on Sunday sales, direct shipping, alcohol content limits, and delivery permissions differ dramatically across state lines. The 21st Amendment protects this state regulatory power from federal interference in most circumstances.