I went to America with my fiancee visa four years ago. I got married as soon as I arrived in America, and we parted after living for three months.

You are married in the United States but not divorced, that is, the literal marriage relationship still exists, which will be very, very unfavorable for you to apply for a tourist visa, because the visa officer may not be sure about your real purpose of going to the United States, whether you will stay, whether you have hidden immigration purposes, and so on.

So you must go through the formal divorce formalities with her as soon as possible. You'd better negotiate with her and get a divorce in China. Because the divorce procedure in the United States is more complicated than that in China. Although you have been married for less than five years, you don't have to appear in court in person (if you have been married for more than five years, you must appear in court in person, not as simple as once or twice), but you still need to follow the procedural time. American states have different laws. California handles divorces less than five years quickly, but it takes six months (six months). Other States generally deal with it once a year. So if you can negotiate with her, it will be easier and faster to get divorced in China. But if you can't contact her, or she doesn't agree to negotiate, then you can entrust a lawyer to unilaterally sue for divorce in domestic courts, but it will take a long time, almost more than a year.