California was the first state to legalize marijuana for medical use. However, since then, other states have legalized even recreational use of marijuana.
Colorado and Washington were the first states to legalize the recreational use of marijuana in November 2012. Before that, there were many states, and still are, that legalized medical marijuana, but Colorado and Washington paved the way for marijuana reform.
Oregon and Alaska followed suit in 2014, totaling four states who legalized marijuana.
As of 2015, here is the map of states who have legalized medical marijuana and/or marijuana: