Countless foreigners have been unlawfully present in the U.S. for such a long time that they have become trapped inside the country. While it is true that they are not physically impeded from leaving, the punishment that looms is almost always a monumental deterrent from doing so. For those who have been unlawfully present in the U.S. for more than six months, the act of leaving would immediately trigger a 3-year bar on returning. Worse yet, for those who were unlawfully present in the U.S. for one year or more, the bar on subsequent reentry increases from three years to ten. Ouch. Now, if you find these penalties to be harsh, you're not alone in your view. Many consider these bars to be the result of what could be described as the harshest set of immigration laws to ever hit the books: The Illegal Immigration Reform and Immigration Responsibility Act of 1996, commonly called "IIRIRA".
Before your jump to conclusions, IIRIRA is actually a bipartisan creation, hammered out by a Republican Congress and signed into law by a Democrat President, President Clinton. Among those who suddenly find themselves most entangled in its web are foreigners who entered the country illegally, usually with the aid of a Mexican human trafficker or "Coyote", and married an American at least one year later. While marriage to an American automatically provides generous exemptions to foreigners who violated any one of a variety of U.S. immigration laws, foreigners who entered the U.S. by sneaking through the border are not exempted from having to return to their home countries and visit the respective U.S. consulate before qualifying to receive a "Green Card". This where a major problem arises.
Since leaving the U.S. will trigger a 3-year bar or a 10-year bar, an application for a waiver of the respective bar needs to be submitted prior to leaving the U.S. This is called an I-601A application. However, even if approved, there is no guarantee that the foreigner will be able to return to the U.S. in the future. Regrettably, U.S. Consulates have been denying Immigrant Visas to foreigners on the basis that they engaged in activities that render them ineligible to received U.S. permanent residence.
One of the most common reasons for denying Immigrant Visas in Mexico is for financing human trafficking. If the U.S. Consulate finds that an applicant could be considered to have funded human trafficking, as convoluted as the funding route may have been, the foreigner will not be granted U.S. permanent residence and would be stuck outside of the U.S.A. Accordingly, if a person admits to having been in the U.S. and sent funds home to relatives, the Immigrant Visa will be denied if the family paid a "Coyote" to traffic a different relative into the U.S.
Foreigners often characterize this outcome as deceptive, even labeling it "trickery". Be that as it may, that is the current state of U.S. immigration law on the issue, and it's better to sidestep the problems that arise rather than attempt to swim against the proverbial tide. Check and double check that there would be no other reason, other than overstay, for a U.S. Consular Officer to deny your request to become a U.S. Permanent Resident based upon your marriage to an American.