A knowledge of past immigration trends helps put our present mass immigration into perspective. In the Historical Data section, we present official records of the annual admission of legal immigrants.

The thumbnail descriptions of Early Immigration Legislation that laid the basis for our current immigration system is from an INS publication.

Descriptions of major provisions of recent immigration legislation for the 1950s and 1960s and for the 1970s to the present comes largely from a Congressional Research Service (Library of Congress) study.

Other historical information may be found in the ISSUES briefs. For example: see An Historical Perspective, The Immigration "Great Wave" in Retrospect and Immigration Now and Then.