What major legislation was ratified on January 16, 1919?

The major legislation ratified on January 16, 1919, is the National Prohibition Act. This act established the legal framework for the prohibition of alcoholic beverages in the United States, which was part of the larger temperance movement aiming to curb alcohol consumption due to its perceived negative effects on society. The National Prohibition Act, also known as the Volstead Act (which provided for the enforcement of the 18th Amendment), defined what constitutes intoxicating liquors and set the rules for enforcement.

While the Volstead Act is often discussed in conjunction with the National Prohibition Act, it specifically refers to the enforcement mechanisms rather than the prohibition itself initiated by the 18th Amendment. The repeal of Prohibition occurred later in 1933 with the 21st Amendment, and the Intoxicating Liquor Act is not broadly recognized as a key piece of legislation associated with the initiation of Prohibition. Thus, the correct focus here is on the National Prohibition Act, which is the foundational law that established the prohibition era in the United States.