In the United States, the legal landscape regarding marijuana is a complex and contradictory jigsaw puzzle. Federal law defines marijuana as an illegal drug, while individual states have witnessed an irreversible trend towards legalization over the past three decades. Since California set the precedent in 1996, the process of legalizing marijuana has profoundly changed social attitudes, economic structures, and legal frameworks.

Marijuana has not always been regarded as a "drug" in the United States. In fact, prior to the early 20th century, the use of marijuana was legal for most of history. The turning point occurred between 1916 and 1931, when 29 states took the lead in enacting bans. The Marijuana Tax Act of 1937 essentially prohibited the circulation of marijuana at the federal level. However, the pendulum of history has swung again. In 1996, California voters passed Proposition 215, establishing the legality of medical marijuana through a referendum, which is widely regarded as the beginning of the modern marijuana legalization movement. The core of California's move was to treat the issue of marijuana regulation as a matter of "state rights," thus creating a direct and lasting confrontation with the federal ban.

Current landscape: A significant conflict between federal and state laws. To date, marijuana remains regulated under the Controlled Substances Act at the federal level and is classified as a "Schedule I controlled substance," meaning it is deemed to have no recognized medical use and a high potential for abuse. This classification is seriously inconsistent with the practices of most states. State laws can be roughly divided into three categories:

Fully legal states: 24 states and the capital, Washington, D.C., have fully legalized both medical and recreational marijuana. These states are mainly distributed in the West, the Northeast coast, and the Great Lakes region.

Medically legal states: Another 15 states only allow the legal use of medical marijuana, while recreational use remains prohibited or only decriminalized (such as North Dakota).

Fully prohibited states: Currently, there are still a few states (such as Idaho, Wyoming, Kansas, etc.) that have not legalized marijuana for either purpose.

Even in legalized states, there are huge differences in terms of possession limits, cultivation regulations, commercial sales licenses, and tax policies, resulting in various regulatory models.
The multidimensional impacts of legalization: taxation, healthcare, and concerns. The effects brought about by legalization are complex and multidimensional: 1. Economy and taxation. The legal cannabis industry has become an important source of tax revenue and a field for job creation in many states. Commercial sales have brought considerable fiscal revenue to state governments. 2. Healthcare system. Studies have shown that in states where medical cannabis is legal, health insurance premiums have decreased, partly because patients have reduced their use of prescription drugs. More data indicate that the mortality rate from opioids in these states has declined, suggesting that cannabis may serve as an alternative analgesic. 3. Social and health risks. At the same time, negative impacts have emerged. States with legalized recreational cannabis have reported an increase in cannabis-related hospitalizations, especially a significant rise in poisoning incidents caused by children accidentally ingesting cannabis-infused foods. Traffic safety issues caused by driving under the influence of cannabis have also continued to attract attention.

Future Trends: Loosening at the Federal Level and Ongoing State-Level Movements
The key variable in the future lies in the adjustment of federal policies. In May 2024, the U.S. Drug Enforcement Administration (DEA) put forward a proposal to reclassify marijuana as a "Schedule III controlled substance". This development made significant progress in December 2025, when President Trump signed an executive order instructing the Attorney General to initiate the process of reclassifying marijuana as Schedule III.
If finally implemented, this will be the most significant change in federal marijuana policy in decades. Although it does not amount to federal legalization, it will greatly reduce the tax burden on the industry (applying general tax laws rather than drug-related provisions) and recognize its medical value.
At the same time, state-level legalization movements are expected to continue. As public support continues to rise and driven by potential economic benefits, the remaining prohibitionist states will face greater internal pressure. There have also been several bills at the congressional level attempting to promote nationwide reforms, but none have succeeded. Many industry observers believe that nationwide legalization, or at least decriminalization, is only a matter of time.
Conclusion
The process of marijuana legalization in the United States is a bottom-up social experiment and legal revolution. It demonstrates the intense collision between state rights and federal laws on specific issues, and how the evolution of public perceptions ultimately drives policy transformation. With the emergence of "loosening" signals at the federal level, this legal landscape is likely to undergo more subversive changes in the next few years. Whether one supports it or not, marijuana has become a long-term issue that cannot be ignored in American society, economy, and politics.