As Rojash has indicated, driving under the influence of alcohol has been an offence, under various road traffic acts, since the earliest days of powered transport.
If your argument centres around the date when the law first quantified the permissible amount of alcohol in a driver's blood (rather than simply having a police officer check whether the driver could walk in a straight line), the year was 1967. (That's when the breathalyser was first introduced in this country).
Chris