From the U.S. Code:
Section 1325 sets forth criminal offenses relating to (1) improper entry into the United States by an alien, (2) entry into marriage for the purpose of evading immigration laws, and (3) establishing a commercial enterprise for the purpose of evading immigration laws. The Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) amended 8 U.S.C. ? 1325 to provide that an alien apprehended while entering or attempting to enter the United States at a time or place other than as designated by immigration officers shall be subject to a civil penalty.
It is also a federal crime to stay in the country for a longer period of time than permitted on a visa.
Amnesty The DREAM Act only rewards illegal behavior for all who break immigration law.