How would have organised crime have developed in America if prohibition was never enacted?
Well, organized crime as we knew it between the wars might not exist without Alcohol Prohibition. But, there is potential for other problems to occur.
One scenario I can think of revolves around cannabis. This drug, already feared by many more reactionary fellows across the U.S.(especially in certain areas), not just because of its association with Mexicans(and later, blacks to an extent), but also thanks to fearmongering campaigns done by W.R. Hearst and company, was a ripe target for banning on at least some state levels.
Let's say that the Mexican Revolution gets a little bloodier and a significantly worse situation develops across the border; remember Columbus? Imagine 20 of them happening all in one event, and if some of the captured Mexicans happened to be smoking a little Mary Jane. That right there, could be a spark for a backlash.
In response to this, Hearst and other newspaper magnates begin to push for a huge backlash against marijuana, with perhaps some support from organizations like the Ku Klux Klan. This proves to be especially popular in the South, where much of the worst racism exists(particularly against the Black community), while in the North, an equally powerful anti-prohibition movement begins to start up. By the mid 1920s, the U.S. is starting to become polarized regionally; while some safehavens for cannabis smokers do exist in the South, such as New Orleans and the growing port town of Miami in Florida, and some northern locales such as Omaha, Cleveland, Columbus, and Indianapolis have banned the drug, the South is becoming increasingly prohibitionist, and the North remains largely prohibition freeSome cities, like New York and Chicago, are quickly developing a cannabis culture as well as San Francisco, and L.A., out West.
Some Southern newspapers(and a few particularly reactionary newspapers up North as well) begin to churn out weekly, and soon, daily, news 'stories' about the supposed ill effects of cannabis and people who reportedly committed various crimes and broke taboos under its influence, and partly thanks to this, increasingly, many are calling for outright prohibition of the drug. In 1930, a man who happens to be the grandson of a man who was one of the wealthiest slaveowners in the entire South, successfully wins the governor's office in Mississippi. And in 1932, with overwhelming support from voters, it becomes the first state to absolutely ban the drug statewide.
By 1938, on the eve of WW2, the only Southern states that haven't banned cannabis are Louisiana, Florida, and Kentucky, the last state having undergone a major surge in Progressive support in recent years. And north and west of the Mason-Dixon line, Ohio, Indiana, W. Va., Pennsylvania, and Idaho have banned cannabis. However, though, it remains legal in all other states.
After World War II, many Americans, including some young GIs, are finding themselves very short on money and with a less effective GI Bill, some less fortunate, and more adventurous Americans begin to turn to gray market means of obtaining a little extra cash. In Missouri in late 1947, a young GI named Jonny Barrett decides to hop up his '29 Ford and turn it into a performance machine. He spends the next 5 years using his car to smuggle marijuana from Missouri, where it's legal, to Arkansas and Tennessee, where it isn't. By 1956, Jonny's built up a reputation and a small cadre of fellow travellers, raising hell all across the South from El Paso to Roanoke.....and there are plenty of copycats in the wings.....