If you are one of the few people who, for one reason or another, did not take advantage of the amnesty opportunities in the 1980s, and if you have been living continuously in the United States since January 1, 1972, you have one final avenue available to get a green card. It is called “registry,” and it is found in Section 249 of the Immigration and Nationality Act (I.N.A.).
To be eligible, you will need to show that you:
You will be required to document all of these facts as part of the registry application process, which is described in “How to Apply for a Green Card Based on Registry.”
How you got to the United States is mostly irrelevant -- you can apply for registry whether you entered on a visa or without inspection (for example by crossing the border illegally), and no matter your current immigration status.
You won’t be barred from registering if you cannot find your passport showing your date of entry, or if USCIS cannot find its own records of your entry.
For most categories of U.S. immigration, you would be denied a green card if you entered the U.S. without inspection by a border official, or if you were a transit passenger or a stowaway, this application is special. In a sense, you are being rewarded for having been able to stay for so long without getting in trouble with the U.S. government.
But there is an exception for people who entered the U.S. on a J-1 visa and are subject to the two-year home residency requirement: They cannot apply for registry unless they first obtain a waiver of the home-country requirement.
If you went for a short trip across the Mexican border or took a month’s vacation in your home country, your departure will probably not be considered an interruption of your required “continuous residence” in the United States. Such absence must be “brief, casual, and innocent.” This means that you must have done nothing either before or during your absence to show that you intended to abandon your residence in the United States.
If you were deported and reentered, that won’t qualify as a brief, innocent, and casual departure. Deportation breaks the continuity of your residence; and reentry after deportation is a crime that will destroy your possibility of showing good moral character.
Similarly, if you quit your job, gave up the lease on your apartment, were feted at good-bye parties, stopped paying your bills, and left the United States with everything you owned, your departure is no longer casual or innocent, however brief it may have been. If there is enough evidence that you intended to leave permanently, USCIS is likely to deny your registry application because you interrupted your continuous residence in the United States.
Like all aspects of immigration law, registry applications are not cut and dried. You'd be well-served consulting with an immigration attorney before starting the application process.