You could be one of many U.S. Citizens who wished that your foreign fiancé(e) who had come to the United States on a J-1, F-1 or B-2 visa stayed in the United States, got married with you and would start an adjustment of status process to obtain a green card without leaving the United States. Your heart is broken when your foreign fiancé(e) returned to her or his home country with the expiration of a visa or completion of studies or training programs. In this case, one of popular options to bring your foreign fiancé(e) to the United States is to go through a K-1 visa process.
A core requirement of a marriage-based green card process is to prove a bona fide relationship. For the purpose of U.S. immigration law, it means that the couple got married with genuine intent of being united in marriage. A sham marriage that circumvents immigration laws for the purpose of falsely acquiring immigration benefits is not valid for immigration purposes.
STEP 1: I-129F