PORTLAND, Ore. – Marijuana stores in Oregon on Thursday began selling to anyone over 21, a major milestone in the decades-long movement to liberalize marijuana laws.

Oregon is the third state to allow pot sales to adults after voters decided overwhelmingly last year to end state sanctions for use and possession of pot, with some restrictions.

More than 250 stores that were already selling medical marijuana to people with health problems opened their doors to the general public. Some opened at midnight, gave away free food and T-shirts, brought a live band or offered discounted marijuana.

THE MARIJUANA MOVEMENT

Oregon was the first state to decriminalize the possession of small amounts of marijuana. The move, in 1973, made pot possession akin to a traffic violation, but it still garnered big fines and a mark on one’s record. Later, Oregon was among the first states to allow people with medical conditions to use the drug with a doctor’s recommendation.

In 2012, voters in Washington and Colorado voted to allow legal sales of the drug to all adults, and they opened stores a year later. In 2014, Oregon and Alaska legalized the drug. Alaska is likely to start selling the drug next year.

WHAT’S DIFFERENT IN OREGON

To start, Oregon is allowing legal sales with limited products, limited quantities and limited regulations.

While state officials work on developing complex rules to govern marijuana growers, testers and sellers, they didn’t wait before allowing sales to begin.

As a result, Oregon starts selling the drug with far more stores and far more product than Colorado and Washington. The state is allowing existing medical marijuana dispensaries, which, until now, could only sell to people with a state-issued card, to serve all adults.

The more than 250 stores dwarfs 24 that were open on Day 1 in Colorado, and the four that were open in Washington. Both states have since opened many more stores.

Oregon isn’t requiring growers to be licensed and isn’t testing the drug for pesticides. That will make it much easier to quickly get pot to buyers.

Due to a quirk in state law, taxes of up to 20 percent don’t kick in until January.

WHAT’S LEGAL

Adults 21 and older can possess up to eight ounces of marijuana in their home and up to one ounce away from home. Other limits apply to marijuana in edible and drinkable forms, as well as mature and immature plants.

Until the full-scale regulations are ready in about a year, only limited products are available for sale to people without a medical marijuana card. They include up to seven grams at a time of dried flower and leaf; four immature plants and an unlimited number of seeds.

Candy, cookies, oil, lotions and other processed products are off limits for now.

Consumption in public is illegal.

WHAT’S NEXT

After their success in four states, marijuana advocates are setting their sights on six more in the 2015 and 2016 elections. They are: California, Massachusetts, Arizona, Ohio, Nevada and Maine.

California, in particular, would be a big prize for the marijuana movement, which has tried and failed to persuade voters in the nation’s largest state to legalize the drug.

The advocates learned from their experiences in the first four states about how to craft a popular initiative and how to appeal to voters. But they still face strong opposition from critics who worry about the health effects and that children will get access.