For many decades now, the only beer you could buy in Kansas grocery and convenience stores was limited to 3.2% alcohol.

But on Monday, that 3.2 beer will be a thing of the past.

“It's a big step for the groceries and the state of Kansas,” says Dennis Toney, an executive with Ball’s Food Stores. “We’ve all wanted this for quite some time.”

Kansas is one of the last states to do away with this Depression-era alcohol, which looks likely to soon die out altogether.

To understand where 3.2 beer came from, you have to go back 86 years to 1933. Nine months before Prohibition was completely repealed, President Franklin D. Roosevelt signed the Beer and Wine Revenue Act, fulfilling a campaign promise.

Because Prohibition was still officially the law, there had to be a limit on the amount of alcohol allowed in beer. Hearings were held and the political process worked out a standard that could gather the necessary votes — 3.2% alcohol by weight.

“The compromise ended up being 3.2 and it frankly, it’s an arbitrary number. There’s nothing magical about it,” says Maureen Ogle, author of Ambitious Brew: The Story of American Beer.

Ogle says that after the federal government legalized all liquor, the 3.2% alcohol by weight standard took hold in lots of states as a middle course between allowing alcohol and not, a sort of temperance light.

“I just call it the long shadow of prohibition,” Ogle says.

Regulators set 3.2 beer apart from other drinks. An influential study in the 1930s labeled it a non-intoxicating beverage.

After Prohibition, states established a crazy quilt of alcohol regulations. Many, including Kansas, made special provisions for 3.2 beer. In some states, it was the only drink allowed. Other states made it easier to buy than stronger beer, wine, and spirits.

Sales of 3.2 were big about 40 years ago, in the 1970s, says Bart Watson, chief economist at the Brewers Association. This was fueled, in part, by teen consumption.

“That’s a time when a lot of states had rules that differentiated consumption for 18 to 21-year-olds,” Watson says.

In other words, 18-year-olds could legally drink, in many states, as long as they were drinking 3.2 beer. Younger kids found it easy to get, too.

American teen drinking peaked in the late ’70s and early ’80s. By the mid-1980s, the country adopted a uniform minimum drinking age, 21. Watson says that one by one, states scrapped special rules for 3.2 beer.

“So the types of carve-outs that said grocery stores, convenience stores, chain retailers can only sell 3.2 started to slowly go away,” says Watson. “Generally this kind of category of 3.2 has been slowly regulated out of existence.”

Oklahoma and Colorado changed their laws last year.

The new standard in Kansas, which takes effect on Monday, April 1, lifts the cap on beer alcohol levels, but only to a degree. The new maximum is 6% alcohol by volume. That will allow for a wide selection of beers but will exclude many high-end craft brews, some of which come in at more than twice the strength the new Kansas limit allows.

Still, brewers are also happy to see the end of the 3.2% alcohol by weight standard.

Jeff Krum, president of Boulevard Brewing Company in Kansas City, talks with distaste about decades of making 3.2 beer for Kansas, Oklahoma and Colorado grocery stores.

“It was just a pain in the posterior, you know, for everyone,” says Krum. “Our brewers, we’re again very excited to get out of the 3.2 business.”

Other brewers have abandoned the segment as well because the market for 3.2 is drying up.

Utah’s will ditch the 3.2 standard on Nov. 1. That will leave just one state, Minnesota, selling 3.2 beer.

And Jamie Pfuhl, president of the Minnesota Grocers Association, says store owners are already starting to have a hard time finding the stuff.

“It does feel lonely and it’s frustrating because nobody wants to be last,” says Pfuhl.

Store owners are already having a hard time finding the stuff.

Frank Morris is a National Correspondent at KCUR. You can reach him on Twitter @FrankNewsman.