It is April 20, which is, of course, the infamous “stoner holiday” in the U.S. and abroad. This “4/20,” take a moment to reflect on why marijuana is illegal and what that means for the U.S.

Marijuana was made illegal in the 1930s through a series of state and federal laws that regulated it further and further. But marijuana had been legal for long before then. The Foundation for Economic Education reported that cannabis was grown in Jamestown, Virginia, an early English settlement in the New World, and that the Spanish had grown it in their South and Central American colonies as well. So, why was it made illegal?

There are a few reasons that marijuana was outlawed, none of them as cut and dry as they were made to appear back in the early 20th century. Marijuana was a cultural tradition to Mexicans, who were coming into the country following the Mexican Revolution. While the cannabis plant had been in the U.S. for years and was present in many medicines at the time, according to drugpolicy.org, the Spanish term for it, “marihuana,” was foreign to most Americans, as was the concept of smoking it. Many Americans did not recognize that marijuana was already frequently used in their daily lives, and isolationist, anti-immigrant sentiments tied marijuana to the new Mexican immigrants.

This ban on marijuana was further pushed for by the Bureau of Prohibition, which had been responsible for the alcohol ban through the 1920s. However, in the early 30s, alcohol was relegalized, and the department had nothing to do. CBS cited that its leader, Henry Anslinger, had previously said that cannabis was not a problem and reportedly called it an “absurd fallacy” to insinuate that it made people violent. However, when alcohol prohibition ended, Anslinger saw a new purpose in cannabis. He claimed that cannabis would turn someone into a “wild beast” and set his sights on a boy, Victor Licata, who had murdered his family with an axe in Florida. Anslinger claimed that the boy had been driven to these actions by marijuana.

He even wrote to 30 leading scientists to ask if cannabis was dangerous. Twenty-nine wrote back to say that it was not dangerous according to an article by the Huffington Post. Anslinger took the one scientist who said it was dangerous and cheered him on in public. The media cheered him on too, and public opinion, as well as legal regulations on marijuana, began to reflect the negative views. It was outlawed, and the U.S. even began to force other nations to outlaw marijuana as well.

Mexico was one of those nations. The Mexican government decided to have its drug policies written by a team of doctors, who all agreed that marijuana did not need to be outlawed. The U.S. retaliated by withholding trade of all legal painkillers to Mexico. Mexican citizens in hospitals died in agony, and Mexico began to regulate marijuana just as the U.S. asked.

There are many other reasons that marijuana was made illegal. The paper trade saw hemp, a cannabis derivative, as a threat and insisted it be outlawed. Some lobbyists called for it to be prohibited, stating that marijuana made white women want to sleep with black men, and that was something that needed to be stopped.

In a nutshell, cannabis regulations were formed in a time when racism in America was rampant. Because marijuana was used by immigrants, it was caught up in that racism. If you decide to celebrate “4/20” this year, remember why it is illegal in the first place, and remember that so many people of color are still disproportionately jailed for using it.