National Prohibition Act was passed in 1919.

To cite the Volstead Act in APA format, you would include the Act's title, its full title ("National Prohibition Act of 1919"), and the year it was enacted (1919). In the reference list, it would look like: National Prohibition Act of 1919, 1919.

if I am reading your question correctly, The Volstead Act (known as the National Prohibition Act of 1919) was a Congressional implementation for the 18th Amendment, which instilled the nationwide prohibition of alcoholic beverages.

It was ratified in 1919

The Volstead Act