1. They may not be eligible to work for several years.
2. If the government thinks the marriage is done for citizenship, expect scrutiny and paperwork.
Americans lead very different lives. If the person marrying someone who is not American is a female, she may be surprised to find out that men in many countries openly do not view women as equal. If it is a male, they may notice a lack of independence.
The main consideration for marrying a citizen of another country is they know each other for a long time.They fall in love. Love has no religion, caste, country. It is something beyond that, people caring for each other with lots of love and affection and understanding each other. So they are getting marry and living happily.