As of now, 20 states have legalized marijuana for medical purposes, and voters in Colorado and Washington have approved marijuana for recreational use. About a dozen more states are expected to legalize marijuana in some form over the next several years.
As of January 31, 2014, passengers traveling internationally into the U.S. and connecting to another flight are allowed to have in their carry-on baggage liquids in excess of 3.4 ounces (100 mL) that were purchased as duty-free merchandise.
Delta allows one bag as carry-on bag, and one personal item, free of charge. The maximum dimensions for the carry-on bag are 22 x 14 x 9 inches (56x46x23cm). This is the size of the bin at the check-in counter, and you may be asked to fit your bag into the bin to confirm it does not exceed this size.