You will be given a $400 Duty-Free Exemption when entering the U.S. with items purchased in St. Maarten/St. martin.
Alcoholic Beverages: One liter (33.8 fl. oz.) of alcoholic beverages may be included in your exemption.
Federal regulations allow you to bring back more than one liter of alcoholic beverage for personal use, but, as with extra tobacco, you will have to pay duty and Internal Revenue Service tax.
While Federal regulations do not specify a limit on the amount of alcohol you may bring back for personal use, unusual quantities are liable to raise suspicions that you are importing the alcohol for other purposes, such as for resale. Customs officers are authorized by Alcohol Tobacco and Firearms (ATF) to make on the spot determinations that an importation is for commercial purposes, and may require you to obtain a permit to import the alcohol before releasing it to you. If you intend to bring back a substantial quantity of alcohol for your personal use, you should contact the Customs port you will be re-entering the country through, and make prior arrangements for entering the alcohol into the U.S. Having said that, you should be aware that……
State laws may limit the amount of alcohol you can bring in without a license. If you arrive in a state that has limitations on the amount of alcohol you may bring in without a license, that state law will be enforced by Customs, even though it may be more restrictive then Federal regulations. We recommend that you check with the state government before you go abroad about their limitations on quantities allowed for personal importation and additional state taxes that might apply.
In brief, for both alcohol and tobacco, the quantities discussed here as being eligible for duty-free treatment may be included in your $400 (or $600 or $1,200) exemption, just as any other purchase would be. But unlike other kinds of merchandise, amounts beyond those discussed here as being duty-free are taxed, even if you have not exceeded, or even met, your personal exemption. For example, if your exemption is $400 and you bring back three liters of wine and nothing else, two of those liters will be taxable.
Links to US Government regulations on duty-free products, alcohol and tobacco: