In a country as large as the United States, how is it possible to count each person residing within its borders?Every 10 years, this is the impossible task that the Commerce Department's Census Bureau takes on. Census 2000 was billed by the bureau as "the largest peacetime effort in the history of the United States." You may recall some of the hoopla surrounding this effort in late 1999 and early 2000 as the nation prepared for National Census Day--April 1.

Counting seems to be the central theme of the United States in 2000, whether it be dimpled and pregnant chads or each citizen living from the tip of Maine to the Aleutian islands off the most western part of Alaska. If you live in the United States, there's a good chance that you received one of the 98 million census forms that were mailed out by the Census Bureau, and on April 1 an adult in each American household was supposed to fill out this form and send it in. More than eight months later, the official tally is in. Census 2000 shows that the resident population of the United States as of April 1, 2000, is 281,421,906. That is a 13.2 percent increase over 1990, when 248,709,873 were counted. See the Census Bureau for details.

The census is required by the U.S. Constitution under Article I Section 2, and is performed once a decade to do more than just satisfy our curiosity about the number of people that live in the country. In this edition of How Stuff Works, you'll learn how the census is actually taken, how its results are used to distribute federal funds and what impact the census has on the U.S. House of Representatives.