What were typical whiskey alcohol percentages back in the and early 1900s before government mandate of 40 percent?

Before the introduction of government regulations, the alcohol content of whiskey varied significantly and there was no standard percentage. Whiskey was often produced and consumed at varying strengths, with some whiskeys reaching an alcohol content of up to 75% ABV (150 proof) or higher.

These high-proof whiskeys were often referred to as "white dog" or "moonshine" and were typically consumed by those living in rural areas or those who produced their own spirits. In general, commercially produced whiskeys during this period were likely to be in the range of 45-60% ABV (90-120 proof).

As governments began to regulate the production and sale of alcohol, they started to set standards and establish minimum alcohol percentages for various types of alcoholic beverages, including whiskey. The establishment of a minimum alcohol percentage of 40% ABV (80 proof) for whiskey in the United States occurred during the Prohibition era as a means to differentiate legal whiskey from moonshine and other illicit spirits.