Los Angeles was sold to 20th century America as a favored place of swimming pools, tans, and movie stars. But if you needed a single dimension to encapsulate the extravagant promise of Los Angeles in that fabulous century, you only had to cite the city's population, and hearers would marvel.
Between 1900 and 1930, Los Angeles grew by 1,300 percent. Between 1930 and 1960, the city doubled in size. It nearly doubled again between 1960 and 2000.
The number of Angeleños was everywhere in boomtown Los Angeles - on postcards to send to "the folks" back East, in brochures from the Chamber of Commerce, and in the pages of the Los Angeles Times. Population summed up all that we wanted to be and how much this place was desired.
The number of Angeleños counted by the 2010 Census - 3,792,621 - doesn't excite that kind of pride any more. The city of Los Angeles grew by just 2.6 percent from 2000 to 2010, the slowest rate of growth in over a century. Los Angeles County grew slightly more - by 3.1 percent - to 9,818,605 residents.
Slowed growth will cost the county at least one seat in Congress and one seat in the state Assembly. Those seats will go to inland, following the migration of Latinos and African-Americans to L.A.'s suburban margins.
This has led to neo-booster hand-wringing and a certain amount of neo-conservative schadenfreude about the "decline of L.A." that the population number is supposed to represent.
But that number says next to nothing. It doesn't reflect the symbiosis between the city of Los Angeles and the counties of Los Angeles and Orange, with a combined population of just under 13 million and an economy that functions more like that of a state than a metropolitan area. Nor can that number distinguish the population centers where new Angeleños are clustering - downtown, for example, which probably reached 50,000 residents in 2010.
And comparison of today's slow growth with yesterday's fevered rate doesn't mean much either. By 2000, our region had finally reached the limits imposed by geography, leaving fairly dense, built-out L.A. with no place for another doubling of population.
Once, a single number summed up the future. But that number always concealed more than it revealed. Counting Angeleños has never given a good account of who they are or what they want L.A. to be.
D. J. Waldie, author, historian, and as the New York Times said in 2007, "a gorgeous distiller of architectural and social history," writes about Los Angeles every Monday and Friday at 2 p.m. on KCET's SoCal Focus blog.