Voters in Colorado and Washington have passed referendums legalizing marijuana for recreational use, which is still banned under federal law.
Colorado's Proposition 64 to the state's constitution makes it legal for anyone over the age of 21 to possess marijuana and for businesses to sell it.
"The voters have spoken and we have to respect their will," Colorado Governor John Hickenlooper said in a statement.
According to ABC News, a similar measure on the ballot in Washington State also legalizes using small amounts of marijuana for people above the age of 21.
In 2005, the Supreme Court struck down a California law that legalized medical marijuana in the state. The Court said Congress had the power to criminalize marijuana under the Commerce Clause, the report added.