Residents in two states voted to legalize recreational marijuana on Tuesday, while those in two other states voted to legalize gay marriage and a third state elected the first gay U.S. senator.

Maine and Maryland became the first states in which voters approved gay marriage. It had failed previously in 32 states, including Maine as recently as 2009.

In addition, Wisconsin elected the first openly gay U.S. senator in history, with Rep. Tammy Baldwin's (D) victory over former governor Tommy Thompson (R).

Colorado and Washington state, meanwhile, became the first states to legalize the production, sale and possession of recreational marijuana. Other states have legalized medical marijuana (including Massachusetts on Tuesday).

Colorado Gov. John Hickenlooper (Associated Press)

But Colorado Gov. John Hickenlooper (D) sounded a cautionary note Tuesday, warning Colorado voters that federal law still prohibits marijuana use.

"The voters have spoken and we have to respect their will," Hickenlooper said in a statement. "This will be a complicated process, but we intend to follow through. That said, federal law still says marijuana is an illegal drug, so don’t break out the Cheetos or gold fish too quickly.”

In Oregon, the third state attempting to legalize recreational marijuana, the measure was falling short of majority support with less than half of precincts reporting.

Washington may also join Maine and Maryland in legalizing same-sex marriage. A measure there led 52 percent to 48 percent with half of precincts reporting.

In Minnesota, a constitutional amendment banning gay marriage was too close to call, with neither side getting majority support.