In 1790, the United States became the first modern nation to undertake a comprehensive count of its population as a routine responsibility of government. The constitutionally mandated decennial census was part and parcel of a revolutionary concept in government. If the new nation's democratically elected governments were to be truly representative of the people, then the government itself would have to make regular efforts to determine just how many of those people there were.

Whereas the Senate was established to represent the interests of the states, the House of Representatives was designed to represent the interests of individuals. The Constitution dictates that every decade a census be used to apportion representatives among the states according to the relative size of their populations.

From the very beginning, the American nation has been characterised by rapid population growth and movement. Hence the census has as much to do with political power shifts as it does with population shifts. With so much at stake, the census has always been a magnet for controversy. George Washington was unhappy with the first ever count of the American people. (He thought that it was too low.) True to tradition, the 2000 census, which will be conducted on April 1st, will be greeted with grumbling from all sides.

Indeed, over the past few years the 2000 census has been shaping up as the most contentious since 1920, when rural lawmakers refused to reapportion House seats based on data showing that more Americans lived in cities than in the countryside. On the surface, contemporary Democrats and Republicans have been fighting over methodology: whether the Census Bureau should employ sophisticated statistical sampling techniques or an old-fashioned head count.

But the real battle has been over who will be counted. Despite its $2.6 billion price tag, the 1990 census was a debacle, leaving an estimated 10m people uncounted, many of them members of Democratic-leaning minority groups. To avoid repeating such a massive undercount in 2000, the Census Bureau had been advocating the use of sampling-a process whereby 90% of people are physically counted and the remaining 10% are statistically inferred. Hoping a higher tally of minorities would help them create new friendly political constituencies, the Democrats championed the bureau's cause, but to no avail.

Citing the Constitution-and not so secretly wishing for another undercount-the Republicans opposed sampling. They demanded the actual (and perhaps impossible) enumeration of every person in the country. A former House Speaker, Newt Gingrich, went as far as to call sampling a "dagger pointed at the heart" of the Republican majority and filed suit against the government to stop it. The Supreme Court ruled in his favour and ordered the Census Bureau to conduct a traditional enumeration.

Therefore it is a foregone conclusion that the 2000 census will vastly undercount the American people. Despite a scheduled $100m national ad campaign to "make everyone count", Americans of all stripes will duck census counters out of a distrust of government and a growing concern for privacy.

The variety of recent immigrants means that language barriers will pose significant challenges to the Census Bureau in 2000. Nonetheless, the new data will reveal a nation that is becoming more racially and ethnically complex than ever before. In the 2000 census, America will be more heavily Latino than it was in 1990. And in part due to the anti-immigration fervour in the first half of the decade, more immigrants will be naturalised American citizens than ten years before.

Yet, even while documenting the diversification of the American people, the 2000 census will also mark the beginning of the end of America's archaic official racial accounting scheme.

In 2000, for the first time, Americans will be able to identify themselves as multiracial. While not necessarily the best solution, the Census Bureau will nonetheless allow respondents to tick any or all of the four primary racial boxes: African-American, white, Asian/Pacific Islander, or American Indian/Alaska Native. In the past, the Census asked respondents to pick only one of the above categories. (Hispanic remains a separate ethnic-and non-racial-classification.)

The multiple-race option came after three years of emotional public debate between multiracial activist and traditional minority civil-rights groups. The Clinton administration rejected a proposed self-standing "multiracial" category that would have included all people of mixed racial background.

Lobbied hard by ethnic advocacy groups that feared the diminishment of their constituencies if a multiracial category had been approved, the White House stumbled on the multiple race option as a political compromise. Census 2000 will acknowledge multiracial Americans even while upholding the old classifications.

However modes, the change in rules will affect policies like affirmateive action or the drawing of minority legislative districts. But the most long-lasting consequence of the new census form is likely to be administrative confusion. It is not at all clear how the multiracial data will ultimately be used. Will the daughter of an African-American father and a white mother be considered black when state legislatures are attemption to forge black-dominant political districts? And what about a citizen who says he is a combination of black, Asian, and white? Will the government consider him all or none of the above?

Despite the steady increase in Asian immigration to the United States, the 2000 census might very well count fewer Asian-Americans than in 1990. In a 1996 test run, 30% of Asian-American respondents identified themselves as multiracial.

And although the Census Bureau does not expect many Americans to tick more than one box in 2000-past policy has encouraged people to choose one heritage over the other-multiracial Americans will increasingly make their presence felt. Since 1970, the population of multiracial children has quadrupled in the United States. Between 1960 and 1990, the number of once-illegal unions between races increased 900%. In contemporary California, one in every six births is a mixed-race child. However flawed, the 2000 census will officially mark America's new found freedom not just to acknowledge its past, but also its future heritage.