It wasn't so long ago that the District was not only the center of the Washington area; it also was its most populous political jurisdiction.

As recently as the 1950 census, the District's 802,178 residents constituted 54.8 percent -- a shade more than half -- of the region's 1,464,089 population. That, for what it's worth, was the Washington area that I began covering in the 1950s, when commuter traffic congestion gave birth to the idea of building Metro.

A reporter colleague, Lawrence Feinberg, reported the other day on how much change has occurred in the intervening years. According to the Census Bureau, two suburban jurisdictions -- Maryland's Prince George's County and Virginia's Fairfax County -- have surpassed the District's population. A third jurisdiction, Montgomery County, is edging close. The District's share is a shade over 15 percent of an officially defined regional total of nearly 3.4 million.

Here are the Census Bureau's estimated 1983 figures: Prince George's County, 674,400; Fairfax County, 649,000; the District, 623,000; and Montgomery County, 603,900.

The District's 802,179 population in 1950 was its official peak. At the turn of the century, in 1900, it was 278,718. Its biggest growth period was in the New Deal decade of the 1930s; it grew by 176,222 people in a decade to 663,091 in 1940, finally topping San Francisco on the list of the nation's big cities.

It's fascinating to look back, too, on suburban population trends. Before intensive suburbanization -- that is, up until the 1920s -- Fairfax County's rural population exceeded Arlington County's suburban population. Beyond that, in 1910, incredible as it seems today, Loudoun County had more people (21,167) than Fairfax County (20,536). Arlington had a scant 10,231.

By comparison: 1983 census estimates show Fairfax with 649,000; Arlington with 152,300, and Loudoun with 61,300.

Across the Potomac, Montgomery County held a razor-thin edge over Prince George's in the 1900 census (Montgomery, 30,451; Prince George's, 29,989) but better trolley service and highway connections, along with lower-cost housing, soon caused the numbers to be reversed. But a lot of social and transportation factors have narrowed the gap, as indicated above.