0^772 POPULATION AND ITS DISTRIBUTION. 371 



and, as well as the most of New York, Pennsylvania, and New 

 Jersey, show the results of commerce and manufactures, where 

 they are firmly established and constitute the leading occupations 

 of the people, which has to a large extent been withdrawn from 

 the country and been grouped in the suburbs of cities and large 

 towns ; so the population, which twenty or thirty or perhaps forty 

 years ago did not increase in such localities, is, under the activity 

 stimulated by profitable occupations, increasing rapidly ; but in 

 the central parts of Maine, New Hampshire, Vermont, and New 

 York, where the transition from agriculture to commercial and 

 manufacturing industries is still developing, population does not 

 gain with very great strides. The changes from agriculture to 

 commercial and manufacturing pursuits are indicative always of 

 a transition from a permanent to an actively increasing density 

 of population. This is evident in the upper Mississippi Valley 

 and in Virginia, where the transition is becoming apparent. The 

 areas known as the plains of the Cordilleran region are being 

 peopled rapidly. This is particularly true in the northern por- 

 tions. Cheap lands and easy tillage of the virgin soil are making 

 the competition of Eastern agriculturists unprofitable, and so the 

 farming population of the far Eastern States is recruiting the ter- 

 ritory embracing the rich lands of the West. In Nevada we wit- 

 ness the peculiar spectacle of a loss of population resulting from 

 the low condition of the mining interests. These facts as to in- 

 crease and decrease give an indication of the ever-changing feat- 

 ures relating to the density of population in great areas. 



Taking the whole country, the progress of growth has been 

 along the thirty-ninth parallel of latitude. The center of popula- 

 tion, meaning thereby the center of gravity of the population of 

 the country, each individual being assumed to have the same 

 weight, was, in 1790, twenty-three miles east of Baltimore, Md, 

 In 1890 it was twenty miles east of Columbus, Ind., five hundred 

 and five miles west of the point at which it was located one hun- 

 dred years ago. The variation of the center from latitude 39°, 

 north or south, has been very slight, the extreme having been less 

 than nineteen minutes, while the movement in longitude has been 

 nearly 9^°, On the basis of a uniform movement on the thirty- 

 ninth parallel of latitude, the westward march for the first decade 

 after the census of 1790 was forty-one miles ; for the second, thirty- 

 six miles ; for the third, fifty miles ; for the fourth, thirty-nine 

 miles ; for the fifth, fifty-five miles ; for the sixth, fifty-five miles ; 

 for the seventh, eighty-one miles ; for the eighth, forty-two miles ; 

 for the ninth, fifty-eight miles ; and for the tenth, forty-eight miles, 

 or an average movement each decade of fifty-five and a half miles. 

 The position of the center of population at each census is accurately 

 shown by the following table and the map which accompanies it : 



