I'm divorced from my wife. My brother (a ...

The laws regarding immigration are very complicated and it also depends on your current citizenship. You may be able to get a green card (probably not immediately) but I'm pretty sure that the authorities will see this case as a possible sham marriage case.

I just married a US citizen so I'm going though the whole process of immigration. The first question is for how long was your brother and your ex married? There are a few stages in becoming a USA citizen - first of all, after filling the initial papers (marriage license, photocopy of passports and birth certificate of the couple medical test for non american and tax report of the american spouse) the immigrant get temporary working and traveling papers, which are not a green card. After the couple go through an interview and all was checked to be legal (between 5 month to 3 years from filing the paper) the non american spouse get a temporary green card, that after 3 years of marriage and some more paper work become a permanent green card, which does not get canceled even if the couple divorce A green card, however, is not citizenship, meaning that your ex can't vote, she is not allowed to live in the USA less then 6 months a year, and she can not extend the green card rights on other. In order to do that she would have to apply for citizenship (meaning, she needs to have a green-card, file more paperwork about working and taxes, and not leaving on welfare, pass an exam about the american history and pledge to the flag - again, this might take a few months. If she have a permanent green card and already divorced and want to make it possible for you to live and work in the USA, I think she should file for citizenship and only after getting one, to marry you, and then for you to apply for a Green card. Also, I think that if the two of you have a child that was born in the USA it might speed things up for you in getting your green card.

My advice is based on your initial reason(s) for divorcing your wife in the first place, and includes the responses you give to the following two questions...

1. Did your wife divorce you during your first marriage to be with your brother because she cared for him?, or...

2. Was their marriage one based on her needs to obtain a green card &/or citizenship based on your brother's U.S. citizenship status?

If the honest answer to  question "1" is "yes", then case closed --- no need to go any further.  The reason being that if she is just flip flopping back and forth between the two of you, she can not be trusted and is definitely not marrying material.  However, if the answer to question 1 is "no", and to the second (i.e., question "2") is "yes", then I say to pursue your heart's desire, and try to build a healthy relationship here in the United States.  Just be forewarned that the immigration department looks rather closely at the validity and history of all immigrant couples applying for citizenship, and may not be too impressed with your wife's past marriage history --- especially if you two were married and divorced previously in the United States.  They too will think your wife to be fickle when it comes to marriage, and will weaken both your chances in someday becoming U.S. citizens.  Good Luck in your pursuit of happiness and legality of citizenship!!!!!!!!! 

p.s. - Lily gives accurate information regarding the rules and regulations required for both green card distribution, and subsequent citizenship requirements.  However, her very final comment may not still be necessarily true.  In the past this would have been perfectly true, but I recently read about a deportation case involving a mother who had given birth to a baby here in the United States, but not only did this not help her with her immigration issues; it also did not automatically make the baby a U.S. citizen as this type of U.S. birth would have automatically provided in the past.  Laws are presently toughening and are now being interpreted differently every day so be aware of this trend.