750 



POPULATION, THE CENTER OF, IN THE UNITED STATES. 



in 1880 was found to be in latitude 39 4' 8", 

 longitude 84 89' 40". This places it in Ken- 

 tucky, one mile from the south bank of the 

 Ohio River, and one and a half mile southeast 

 of the village of Taylorsville. That is, it is 

 eight miles west by soutli from the heart of 

 the city of Cincinnati. This position is shown 

 in the diagram on page 755. 



The method by which this determination 

 was made may be briefly explained. 



A point was first assumed as nearly as possi- 

 ble to the true position of the center. Through 

 this point a parallel of latitude and a meridian 

 of longitude were drawn. In this case the cen- 

 ter was assumed at the intersection of the par- 

 allel of 89 with the meridian of 84 30', which 

 lines were taken as the axes of moments. 



A north or south moment is the product of 

 the population by its distance from the as- 

 sumed parallel ; an east or a west moment is 

 the product of the population by its distance 

 from the assumed meridian. In the first case 

 the distances were measured in minutes of 

 arc; in the second case it was necessary to 

 use miles, on account of the unequal length of 

 the degrees and minutes in different lati- 

 tudes. The population of the country was 

 then grouped by square degrees, i. e., by areas 

 included between consecutive parallels and 

 meridians, as they are convenient units with 

 which to work. The population of one hun- 

 dred of the principal cities was then deducted 

 from thnt of their square degrees and treated 

 separately. Then the population of each square 

 degree was assumed to be at its geographical 

 center, except in cases where this was mani- 

 festly an incorrect assumption. In these cases 

 its position was estimated as nearly as pos- 

 sible. The population of each square degree, 

 and of each city north and south of the as- 

 sumed parallel, was multiplied by its distance 

 from that parallel, and the sum of the north 

 and of the south moments made up. Their 

 difference, divided by the total population of 

 the country, gave a correction to the latitude, 

 the sign of the correction being positive if 

 north, negative if south. In a similar manner 

 the east and the west moments were made up, 

 and from them the correction in longitude was 

 made. 



The above is, essentially, the method hereto- 

 fore pursued for determining the center of 

 population ; and, for purposes of comparison, 

 it was employed in 1880. 



The center of population in 1870, as at the 

 time of the census preceding, was computed 

 by a method differing in some details from 

 that above. For this purpose a point was as- 

 sumed entirely outside of the country, and 

 correction made therefrom to the true center. 

 Instead of the square degree, the county was 

 taken as a unit, and the lever-arm of the popu- 

 lation of the county was taken as the distance 

 from the geographical center of the county to 

 the axes of moments. The labor involved in 

 this method was much greater than that in the 



last method, inasmuch as many more units 

 were used, and as the length of the lever-arm 

 differed in every case. 



In 1790 the center of population was at 

 89 16-5' north latitude and 76 11-2' wot, 

 longitude, which a comparison of the best 

 maps available would seem to place about 

 twenty-three miles east of Baltimore. During 

 the decade of 1790 to 1800 it appears to have 

 moved almost due west to a point about eight- 

 een miles west of the same city, being in lati- 

 tude 39 16-1' and longitude 76 56'5'. From 

 1800 to 1810 it moved westward and slightly 

 southward to a point about forty miles north- 

 west by west from Washington, being in lati- 

 tude 39 11-5' and longitude 77 37'2'. The 

 southward movement during this decade ap- 

 pears to have been due to the annexation of 

 the Territory of Louisiana, which contained 

 quite extensive settlements. 



From 1810 to 1820 it moved westward, and 

 again slightly southward, to a point about six- 

 teen miles north of Woodstock, Virginia, being 

 in latitude 89 5'7' and longitude 78 33'. This 

 second southward movement appears to have 

 been due to the extension of settlement in Mis- 

 sissippi and Alabama, and in Eastern Georgia. 



From 1820 to 1830 it moved still westward 

 and southward to a point about nineteen miles 

 southwest of Moorefield, in the present State 

 of West Virginia, being latitude 38 57'9' and 

 longitude 79 16'9'. This is the most decided 

 southward movement that it has made during 

 any decade. This appears to have been due 

 in part to the addition of Florida to our terri- 

 tory, and in part to the great extension of set- 

 tlements in Louisiana, Mississippi, and Arkan- 

 sas, or generally, it may be said, in the South- 

 west. 



From 1830 to 1840 it moved still farther 

 westward, but slightly changed its direction 

 northward, reaching a point sixteen miles 

 south of Clarksburg, "West Virginia, being in 

 latitude 39 2' and longitude 80 18'. 



During this decade settlement had made de- 

 cided advances in the prairie States and in the 

 .southern portions of Michigan and Wisconsin, 

 the balance of increased settlements evidently 

 being in favor of the Northwest. 



From 1840 to 1850 it moved westward, and 

 slightly southward again, reaching a point 

 about twenty -three miles southeast of Parkers- 

 burg, West Virginia, latitude 38 59' and longi- 

 tude 81 19', the change of direction southward 

 being largely due to the annexation of Texas. 



From 1850 to 1860 it moved west, and 

 slightly northward, reaching a point twenty 

 miles south of Chillicothe, Ohio, this being in 

 latitude 39 0'4', longitude 82 48'8'. 



From 1860 to 1870 it moved westward and 

 sharply northward, reaching a point about 

 forty-eight miles east by north of Cincinnati. 

 This northward movement is due in part to the 

 waste and destruction in the South consequent 

 upon the civil war, and in part, probably, to 

 the fact that the census of 1870 was defective 



