Answer:
1. The census is the US government’s largest peacetime operation. At its peak for the 2010 census, more than one million census workers counted roughly 310 million people in some 120 million households.
2. Since the first US census in 1790, certain segments of the population have been consistently under reported. They also often have a vested interest in avoiding the watchful eye of the government.
3. Traditionally, various agencies of the US government have backed away from aggressively pursuing and deporting illegal immigrants ahead of the official census count day. The Census Bureau allocated an additional $250 million for the 2010 census for advertising and outreach programs to help boost participation rates in the traditionally under reported groups.