Laws allowing the recreational use of marijuana come into effect in the state of Washington.
In defiance of federal law, which classifies cannabis as an illegal narcotic, both states have voted in favour of removing criminal penalties for the personal possession and consumption of 'weed'.
In Colorado the vote came down to nearly 53% in favour versus 47% against.
Both states in question now allow those above 21 years of age to legally purchase up to an ounce of cannabis. Although Colorado also allows the personal cultivation of up to 6 plants, it is still illegal to grow cannabis in Washington state.
Cannabis consumption for medical purposes was already permitted in both states and seventeen others. During the November elections , Massachusetts joined the list when it adopted a more lenient approach towards medicinal marijuana.
Those who support the changes have long argued that legalization would strike a blow against drug cartels and generate millions in revenue through sales tax.
A system designed to control the cultivation and consumption of cannabis is still in the beginning stages of development. For now, the measures implemented are modelled on those that determine the sale and consumption of alcohol.