The Census Bureau initiated the American Community Survey (ACS) development program in 1994 to develop and test the feasibility of producing long form data on a yearly basis, instead of once a decade. In 2001, the Census Bureau initiated the ACS Research and Evaluation Program to answer questions about the usability and reliability of the ACS estimates. This report is an evaluation from that program. The report compares selected quality measures for the 1999 – 2001 ACS three-year average estimates to selected quality measures for the Census 2000 long form estimates.