While some states allow cannabis, there is still a Federal ban at this time. If you are entering the USA, please check up to date laws on the topic. Currently you can not take THC or CBD in to the US.
“The recreational use of cannabis is legal in 9 states (Alaska, California, Colorado, Maine, Massachusetts, Nevada, Oregon, Vermont, and Washington), the District of Columbia, and the Northern Mariana Islands. Another 13 states plus the U.S. Virgin Islands have decriminalized. Commercial distribution of cannabis is allowed in all jurisdictions where cannabis has been legalized, except Vermont and the District of Columbia.”