According to just-released 2010 Census results, the city of St. Louis experienced an unexpected loss in population from 348,000 in 2000 to 319,000 in 2010. This was surprising since the latest population estimate was 357,000 (2009). The new population figure however provided exoneration for the Census Bureau, which had been challenged six separate times during the decade on its city of St. Louis population estimates. The higher 2009 population estimate was the cumulative effect of those six successful challenges. In fact however, without the challenges the city of St. Louis population would have been 311,000, much closer to the final count of 319,000 people.
Among the world's municipalities that have ever achieved 500,000 population non-have lost so much as the city of St. Louis. The new figure of 319,000 people is 63 percent below the 1950 Census peak of 857,000 people. Indeed, the 2010 population is nearly as low as the population in the 1870 census.
Even so, the population loss of the last decade belies the progress that has been made in converting warehouse buildings, office buildings and other disused structures into urban residential areas, especially along Washington Avenue. These developments, among the largest in the United States, however, fell far short of preventing the population loss.
The St. Louis Metropolitan area did much better. In 2010, the metropolitan area had a population of 2,813,000, up from 2,699,000 in 2000, a gain of four percent. The loss in the city was eight percent, while the suburbs gained six percent.