In Colonial times the drinking water contained bacteria that would give people dysentery and cholera. Therefore many people preferred to drink alcoholic beverages which did not make them sick. We now understand that boiling the water kills harmful bacteria during the process of brewing and distilling.
In the 1700's, alcohol consumption was regarded as just another drink. It was consumed regularly throughout the day. The average colonist drank approximately seven gallons of alcohol per year, over 3 times what American's drink now.