The data contained in the Relationship files is extracted from the Census Bureau's internal TIGER® database. The Census 2000 block relationship files portray the following relationships between the 1990 and the 2000 Census Blocks:
The Census Bureau has provided relationship files to help data users meet their many and diverse needs. The majority of data users will need only the 1990 tabulation census block to Census 2000 tabulation block relationship file to see how 1990 tabulation blocks now correspond to Census 2000 blocks.
The Census 2000 Block Relationship Files were created for the 50 states, the District of Columbia, Puerto Rico and the following Island Areas: American Samoa, Guam, Northern Mariana Islands and the U.S. Virgin Islands.
Note: The 2000 collection blocks are the blocks used in the Census data collection phase by our Field staff. The 2000 tabulation blocks are the blocks used in the final data tabulations.