Unfortunately, there is no easy answer to this question. The DREAM Act was never passed by the Congress and the options are very limited. However, they do exist. There are citizenship venues available to a person who entered the US without inspection ("EWI"), i.e. illegal undocumented alien. The first is a waiver. If you entered US illegally, marriage to the US citizen does not by itself entitles you to a permanent resident status and you need to seek a waiver. Such types of waivers are very case specific and you should consult an immigration attorney to discuss your circumstances. Once a waiver is granted, an alien who is married to the US citizen may reenter the US legally and eventually file for the US citizenship. Generally, an undocumented illegal alien may file for a waiver based on a hardship to the US citizen spouse. This waiver can only be filed from the outside of the United States. An illegal alien will have to leave the US and go back to his home country. Since this waiver is discretionary it may get denied if US immigration services finds that the hardship to the US citizen spouse is not extreme enough to admit the alien back into the US. In addition, the correct answer also depends on the amount of time an alien spent in the US undocumented. For example, if an alien has been previously removed and reentered the US without inspection again, or even if he reentered the US without inspection multiple times. In such cases, a waiver may not be available until after an alien spends 10 years outside of the US.
There is also an option of cancellation of removal if the illegal alien gets detained by the USCIS. If an alien has been in the United States for at least ten years and if his removal/deportation would cause exceptional and extremely unusual hardship to US citizen spouse, parent or child who is a US citizen or permanent resident, he may qualify for Cancellation of Removal. It is very difficult to prove such level of hardship, but if an alien is granted Cancellation of Removal, he will be eligible for permanent residence.
Please contact an experience immigration attorney to discuss possible resolutions of your particular case. The responses and information are intended to be general and should not be relied upon for any specific situation. Best of Luck!
You can get married, but you will not be able to adjust your status here because you enterred the US illegally. After Immigration approves the application, they will likely forward to the Dept of State to process through your country of origin. Your other option is to apply and if they deny it and put you in removal proceedings, then you can apply for cancellation of removal in court, which will grant you permanent residence--if your removal is cancelled. Two of the main requirments for cancellation of removal are being a resident for ten years and having a US citizen sponsor. This is a complicated process and you may not be able to applu for cancellation of removal until you are put in removal proceedings.