Canada has legalized the possession and use of recreational cannabis becoming only the second country in the world to do so after Uruguay, although Portugal and the Netherlands have decriminalized the drug.
Prime Minister Justin Trudeau, the leader of the governing Liberal Party said the new law is designed to keep drugs out of the hands of minors and profits out of the hands of criminals.
Adults will be able buy cannabis oil, seeds, plants and dried cannabis from licensed producers and retailers and to possess up to 30 grams of dried cannabis in public. It will also be legal to grow more than four plants per household.
The markets for cannabis opened on Wednesday at midnight amid lingering questions about the impact on health, the law and public safety. But there remain concerns, including about the readiness for police forces to tackle drug impaired driving.
Canadian provinces and municipalities have been preparing for months for the end of cannabis prohibition. Provinces and territories are responsible for setting out many of the details for where cannabis can be bought and consumed within their jurisdictions.
Shops in the province of Newfoundland, the most easterly time zone in Canada, opened as midnight struck for the first legal sales of cannabis in the country. A number of analysts are predicting a shortage of recreational marijuana in the first year of legalization as production and licensing continues to ramp up to meet demand.
Ontario, Canada's most populous province, will only begin opening retail stores next spring, though residents will be able to order cannabis online.
With global trends shifting away from a strict prohibition of cannabis, the world will be watching this national experiment in drug liberalization.