Gambling is now legal under federal law in the United States, though there are significant restrictions on interstate and online gambling. Within its borders, each state has the authority to regulate or prohibit the practice. If state-run lotteries are included, nearly every state allows some form of gambling.
The Commerce Clause has been used by Congress to regulate interstate wagering, global betting, and connections between United States as well as Native American regions. It has, for example, passed legislation forbidding the unpermitted transit of lottery tickets among states, outlawing sports wagering with certain special cases, and limiting the amount of gambling permitted on Native American land.
Each state decides what type of gambling is permitted within its boundaries, at which betting can take place, and who can wager. For every state has implemented different laws on these subjects. The states have also different legal gambling age group, with some requiring the same minimum age for all kinds of gambling, while the others require a new age requirement based on the operation. In New Jersey, for instance, an 18-year-old could really purchase lottery tickets or bet on a race but cannot join a casino until she or she is 21. The age restriction is most likely due to the sale of alcohol in that location.