According to U.S. Census Bureau "Apportionment is one of the most important functions of the decennial census. Apportionment measures the population so that seats in the U.S. House of Representatives can be correctly apportioned among the states. Until the middle of the twentieth century, Congress enacted new apportionment legislation following almost every census."
The 1960 U.S. Census resulted in reapportionment of Connecticut's State legislature. In 2001, the Reapportionment Commission created five Congressional districts due to national population shifts identified in the 2000 census.