No. A marriage creates a family relationship between the U.S. citizen and the foreign spouse, which is the starting point for the foreign spouse to be eligible for a green card. The U.S. citizen spouse still has to file an I-130 Petition for Alien Relative with sufficient evidence to prove that the marriage is bona fide and was not entered into to circumvent immigration laws. If the I-130 petition is approved, the foreign spouse can pursue his/her green card by filing an adjustment of status application, if he/she is living in the United States or apply for an immigrant visa at the appropriate U.S. consulate, if he/she is living abroad.