We like to think that we're living in a much more progressive time compared to the past, particularly when it comes to marijuana. But it turns out this decade isn't the first time Americans tried to legalize cannabis. So what happened in those previous attempts?

The first real attempts to legalize marijuana began in the 1970's. In fact, from 1973 to 1978, 12 states decriminalized possession of marijuana. So many states had done so, that by 1979 one-third of Americans lived in areas where possession of cannabis would only result in a fine. This decriminalization movement was mostly built off the anti-war and civil rights protestors from the late 1960's, who largely argued that marijuana was much safer than the actual U.S. government.

In fact, the marijuana paraphernalia industry was pretty lucrative in the 1970's. In 1977, sales of pipes, bongs, rolling papers and other cannabis-related products reached $250 million, which is equivalent to $1 billion today.

So what happened? The short answer: Nancy Reagan.

The longer answer is Americans began to change their minds about marijuana. While many didn't care about decriminalization at first, by the end of the 1970's that began to change. Surveys in 1978 found that nine percent of high schoolers smoked marijuana everyday, and there were reports of young children having easy access to cannabis. This sparked outraged among parent groups who began organizing to shut down paraphernalia shops and other related businesses.

Then in 1981, Ronald Reagan took over as president, and with him came the new first lady Nancy Reagan. As First Lady, Nancy needed a project or movement to get behind, and many parent groups appealed to her to address marijuana issues. She unveiled a national anti-drug campaign ("Just Say No"), and public opinion quickly turned against marijuana. States rescinded their decriminalization laws and soon cannabis was public enemy number one.

So with states legalizing marijuana today, let's remember that support for the drug has come in waves in the past and there's no guarantee that people will unanimously agree to allow cannabis in the years to come.

(h/t Time)