This report opens with brief legislative histories of "comprehensive immigration reform" (CIR) in the 109th and 110th Congresses. A comparative overview of key CIR provisions in the three bills that received floor action in the 109th and 110th Congresses follows. In addition to a narrative discussion of how the bills addressed the main provisions of CIR, the report provides a table that presents a comparative summary of the key features of the bills. The report concludes with observations contrasting the 2006-2007 period with the context of today's CIR debate. The report also provides an appendix that summarizes the three major CIR bills.