23 U.S. states that have legalized medical cannabis.Rhode Island is one of the 23 U.S. states that have legalized medical cannabis. Here is some important information about it: - When the medical cannabis bill was approved by the Rhode Island House and Senate, it was vetoed by the governor. But, it was immediately over-ridden by both the House and the Senate and made effective on January 3, 2006. People who want to be a part of the medical cannabis program - People who want ...