The Immigration Reform and Control Act of 1986 (IRCA) was a manifestation of widespread public concern over the volume of undocumented immigration into the United States. The principal innovation of this legislation - the provision to impose penalties on employers who knowingly hire undocumented immigrants - was a response to this concern. This effort at restriction was tempered in IRCA by other provisions permitting the legalization of two types of undocumented immigrants those who had resided in the United States since January 1, 1982; and what were called special agricultural workers (SAWs), persons who had worked in perishable crop agriculture for at least 90 days during specified periods from 1983 to 1986. Approximately 3.1 million persons sought legalization (what is popularly referred to as amnesty) under these two provisions. The breakdown was roughly 1.8 million under the regular program and 1.3 million as SAWs. Mexicans made up 75 percent of the combined legalization requests.