DENVER — The world's sixth-largest economy legalized recreational marijuana Tuesday as Californians relaxed their restrictions on cannabis use, a decision likely to reverberate across the country and through Congress.

"This is the most important moment in the history of the marijuana legalization movement," said Tom Angell, a spokesman for the pro-legalization Marijuana Majority.

Eight other states were deciding marijuana inititives on Tuesday. Florida, Arkansas, and North Dakota all voted in favor of medical marijuana, and Massachusetts allowed recreational pot. Maine also appeared headed toward approval. Results were still being counted in Arizona, Montana and Nevada.

Twenty-eight states now permit cannabis use for certain medical conditions, including cancer and HIV. Floridians nearly passed a similar measure in 2014, but the measure fell just short of the required 60% supermajority. It won easily on Tuesday, supporters said. North Dakota and Arkansas followed suit later in the evening.

Marijuana initiatives were among the highest-profile of the ballot measures being decided across the country: marijuana-industry experts said the Florida medical marketplace could be worth as much as $1.6 billion by 2020. Because it has such a large population, Florida could represent almost 16% of the country's medical marijuana marketplace, says a study from New Frontier Data and Arcview Market Research. Experts say the suppot for both medical and recreational marijuana will likely increase pressure on federal lawmakers to change their treatment of cannabis.

Elsewhere across the country, voters are also deciding whether to mandate higher minimum wages and require performers in California's pornography industry to use condoms.

Ballot initiatives can give citizens the ability to bypass their elected officials and instead make their case directly to voters, or they can be placed on the ballot by lawmakers seeking to amend the state constitution. In many cases, they permit voters to directly set specific policy when lawmakers can't, or won't, act.

Marijuana issues have drawn the most attention, with nine states deciding whether to loosen the rules governing either recreational or medical cannabis use. Depending on the outcome of those initiatives, the federal government may come under increasing pressure to reconsider its classification as a Schedule 1 illegal drug.

Legalization advocates credit Colorado and Washington, the first two states to permit recreational marijuana sales, with helping lay the groundwork for what they expected to be a series of victories across the country.

"The concept of ending marijuana prohibition was appealing to a lot of people, but it was unclear what that would look like," said Mason Tvert, a spokesman for the pro-legalization advocacy group Marijuana Policy Project. "It’s difficult to win a race when you can’t see the finish line. Now that there is a clear alternative to prohibition that people can actually see is working, they are a lot more comfortable with taking that leap."

PHOTOS: Election Day in America 2016