If one would like to have a slave in the US, Congress has graciously allowed US citizens to apply for their fiancees using the K-1 visa! When an alien enters on this visa, they must marry their US citizen spouse within 90 days, and then they can only get their permanent residence through adjustment of status through that person -- and not through anyone else.
That means, to those of you with evil inclinations, that you may bring your fiancee here, marry her, and then keep her in bondage by refusing to apply for her green card. Your fiancee will have to keep you happy, and hope that in the future you will apply for her -- or she can go home.
There are a few means clever attorneys may use to get around the K-1 entry restriction, but why does it exist in the first place? A spouse who comes over to join her US citizen husband may divorce him on shortly after arrival in the US and keep her green card or get a different green card from another spouse.
Surely the K-1 entrant can be judged as may be the spouse, and we may look to their behavior after they entered the US to determine whether or not they intended to meet and marry their betrothed. There is no need for this ridiculous rule for only fiancees.
In my career as an immigration attorney, I have seen the K-1 visa misused a great deal, and it has been my pleasure to save some nice aliens from their US citizen spouses, despite the K-1 restriction. But if there is no great reason for the restriction, why does it still exist?