Up and down the Western Hemisphere, marijuana policy is a growing topic of discussion, and laws are starting to change. In 2014, retail marijuana stores opened in the states of Colorado and Washington, where anyone over 21 years old can purchase a wide variety of marijuana products.

Pot stashes in Oregon are legal — up to 8 ounces. So is the homegrown, up to four plants a household.

Legalising the medical use of cannabis has not led to a surge in the numbers of adolescents using it in the USA, according to new research that surprised its authors and will encourage those hoping for relaxation of the law elsewhere.

House Republicans advanced a budget plan that would prevent legal sales of marijuana in the District until at least 2017. Advocates for legalization, however, called it a victory.

Dozens of government officials and researchers from a half-dozen U.S. states and a few countries that have legalized marijuana or are at least thinking about it are gathering in Washington state this week for meetings focused largely on one question: How do we know if it’s working? Organizers say it’s crucial to get a better handle on what data are being collected about the impacts of legalization and to consider what further research is needed.

The US Supreme Court has asked President Barack Obama's administration to take a stance on legal marijuana as it considers a lawsuit seeking to ban Colorado’s legalisation of recreational marijuana.

Propelled by successful campaigns in Western states to legalize the recreational use of marijuana, some advocates and legislators say a marijuana legalization race is developing in New England, with millions of dollars in tax revenue riding on the outcome.

Public opinion about legalizing marijuana in the US, while little changed in the past few years, has undergone a dramatic long-term shift.

President Barack Obama cautioned persons who have hopes of marijuana being legalised, as he explained the difference between legalisation and decriminalisation.

Washington's experiment with legal recreational marijuana is "teetering on the brink" of a market failure.

Legislators in Massachusetts are working on a marijuana legalization proposal, in part as an effort to short-circuit an expected 2016 ballot push.

In Washington DC it’s now legal to possess marijuana, to grow it, to smoke it and to give it away.

A new national survey of American voters has found a strong majority in support of marijuana legalization and an even larger majority in support of decriminalization of the drug.

For the first time, the General Social Survey – a large, national survey conducted every two years and widely considered to represent the gold standard for public opinion research – shows a majority of Americans favoring the legalization of marijuana.

Two stories published last week perfectly sum up the state of American drug policy.

Alaska has made smoking, growing and owning small amounts of marijuana legal, becoming the third US state to decriminalise recreational use.

Four states and the District of Columbia have already legalized weed and plans are already afoot in several more for this year or next, either by voter initiative (where that option is available) or through the legislature. But which states will be next, and how fast will the dominoes fall? After all, we're unlikely to see the end of federal pot prohibition until a lot more than four states have legalized it, so how long is it going to take to reach that critical mass? (See also: 7 states that are next in line to legalize marijuana)

Vermont lawmakers are considering whether to become the first state Legislature to legalize marijuana.

Barack Obama’s nominee for attorney general, Loretta Lynch, told senators during her confirmation hearing that she, like her predecessor Eric Holder, would not support marijuana legalization.