Janis Peterson-Lord Immigration Law Blog on Lawyers.com

Each year, hundreds of thousands of U.S. citizens marry foreign nationals and petition for permanent residency status for their spouses.  It is widely believed that marriage visas are a fast pathway to U.S. citizenship.  Not true.

Misconceptions vs. the truths

• If I want a green card all I have to do is marry a U.S. citizen.Although spouses of U.S. citizens are immediate relatives under immigration laws and excluded from quota limitations—marriage to a U.S. citizen does not result in an instant citizenship or U.S. residency.  The belief in automatic citizenship is a widespread misconception further encouraged by film, television, and urban legend.  Furthermore, if a person entered the US without authorization, a marriage to a US citizen does not remove their inadmissibility issue.  They must either show they have an old petition on file (from April 2001 or before) or they must depart the US and apply in their home country, and win their I-601 waiver request.
• Marriage visas are quick and easy to get.  It is possible, if conditions are right, to get a marriage visa within 120 days.  However, the national average for visa processing is currently 10 to 12 months.  So, it is wise to apply for and monitor your marriage visa application progress on the U.S. Citizen and Immigration Services website.
• Once I have my conditional green card, I can divorce my American spouse because my citizenship is assured.  A conditional green card imposes conditions on your permanent residency status.  If your marriage ends within two years, Immigration Services may consider it an admission that the marriage was fraudulent, and you will always have to prove that your marriage remains viable after the two-year period.  If you cannot, you may lose your permanent residency status and have to return to your home country.  Additionally if fraud is proven, it may be up to 10 years before you can return to the United States, and never by marrying another US citizen.

Despite myths and misconceptions, neither permanent residency nor citizenship is automatic.  Acquiring citizenship takes time and perseverance.  Marriage is not a guarantee of legal residence or of U.S. citizenship.  Though getting a conditional green card may take only 3-4 months, getting a permanent green card and then  citizenship can take years.  

Qualified immigration attorneys can provide answers
Immigration and marriage make for a complex set of circumstances.  Filing the wrong forms or the right forms improperly can cause stops and delays.  For more information on how to properly attain a marriage visa for your foreign spouse, ask a qualified  immigration attorney.