Final answer:
In Louisiana, a person must be at least 21 years old to purchase intoxicating liquors, in accordance with the National Minimum Drinking Age Act of 1984. This national mandate aligns with historical U.S. legislation regarding the control of alcohol.
Step-by-step explanation:
A person must be at least 21 years of age to purchase intoxicating liquors in Louisiana. This is part of a nationwide regulation that stems from the National Minimum Drinking Age Act of 1984, which required states to set the minimum legal drinking and purchasing age to 21 in order to retain full federal highway funding.
Historically, the regulation of alcohol, including the ratification and eventual repeal of Prohibition (as defined by the 18th and 21st Amendments to the U.S. Constitution), has played a significant role in U.S. law. The laws regarding the prohibition of the transportation or importation into any state of intoxicating liquors, in violation of the laws thereof, are designed to comply with these long-standing national standards.