Mean center of U.S. population was once in Loudoun County

On their farm west of Waterford, Cheryl and Michael Morrison stand near a quartz stone that 200 years ago probably marked the mean center of the U.S. population, which was 7.24 million people in 1810.
On their farm west of Waterford, Cheryl and Michael Morrison stand near a quartz stone that 200 years ago probably marked the mean center of the U.S. population, which was 7.24 million people in 1810. (Eugene Scheel)
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Sunday, May 2, 2010

Stopping on Old Wheatland Road west of Waterford recently, I spotted Michael Morrison clearing brush. Curiosity got the better of me, because I knew that 200 years ago, his field in upper Loudoun County had been the mean center of population in the United States.

The Census Bureau had given me the coordinates of the center of population, which was 7.24 million people in 1810. Census data predict that the 2010 population will be 308 million.

I asked Morrison whether he had come across a marker. I didn't expect him to say yes, because five years earlier, I had posed the same question to Jack Hutchison. He had run cattle on the field for about 60 years. He said he hadn't seen one and asked me what the marker might have looked like. I didn't know.

Neither did the Census Bureau. But David Pemberton, a bureau historian, said he knew of some ad hoc markers. In 1920, someone had cited the mean center of U.S. population -- then in Owen County, Ind. -- by carving it into a tree. In 1930, a tombstone-shaped rock in a Greene County, Ind., field marked the center.

David Doyle of the National Geodetic Survey told me he had also heard of local markers of stone or wood in some areas. Since 1960, the survey has been responsible for placing markers "at or near the centers of population," Doyle said, adding that he knew of no Loudoun monument.

Without getting into complex math, one might think of the mean center of population as the point where two straight lines from a foursome of bridge partners intersect, each player representing a unit of population.

The Census Bureau's definition reads "the point at which an imaginary, flat, weightless and rigid map of the United States would balance if weights of identical value were placed on it so that each weight represented the location of one person."

Morrison, who said he had been "over every inch" of the 25-acre field, which he and his wife, Cheryl, had bought in 2007, asked me what the marker might look like. Again, I said I didn't know.

Then he mentioned a flat piece of quartz imbedded on a knoll. So we took a bumpy ride down to it on a golf-course-like jitney.

There, nearly hidden by lush grass, was an elongated piece of quartzite, almost two feet in length, with a broken edge. Some weathered striations on top could be interpreted as a Christian cross with a missing arm.

The location was about 400 feet north of the spot I had plotted from the coordinates of latitude and longitude. Because I knew that determinations of coordinates shifted through the years, I asked Doyle and Pemberton whether they could pinpoint the date of the computations I was using.

They could not come up with a specific year, although both named the early 1950s as a probability. In 1950, the U.S. territories of Alaska and Hawaii were entered into the equation (they became states in 1959). Before then, the base was the contiguous 48 states.


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