Now if you will take the data at the foot of the page and work the calculation to the year 2000 (allowing for the gradual slackening of the increase) what will the population of the United States be then?[7] It will be around three hundred millions, which is more than the white population of the entire world today. Even so the country would not be nearly so thickly populated as some European countries now are. Today there are in the United States about thirty-five persons to the square mile. But there are 700 to the square mile in England and 658 per square mile in Belgium, which are two of the most thickly-populated of all countries at the present time.[8] Three hundred million people in the United States, if the figure should reach that total at the end of the twentieth century, would be less than one hundred per square mile. There would still be six acres of ground for every man, woman and child in the country. Whether there would be a sufficient food supply to support so large a population is another question and one which is not so easily answered. ------------------------------------------------------------------------ THE CENTER OF POPULATION The way in which the center of population has been steadily moving westward is indicated by this map. It will be noted that in its journey to the west it has held closely to the 39th parallel of latitude. The median point, on the other hand, has remained practically fixed during the last thirty years. The location of the median point is determined as follows: Take the parallel of latitude which divides the country in such manner that half the population is north of that parallel and half is south of it; similarly, take the meridian of longitude which divides the country in such manner that half the population is east of it and half is west of it; the intersection of this parallel and this meridian is called the median point. [Illustration: CENTRE OF POPULATION AT EACH CENSUS: 1790 TO 1920 MEDIAN POINT 1880 TO 1920 ☆ CENTER OF POPULATION Δ MEDIAN POINT ] ------------------------------------------------------------------------ [Sidenote: Some areas are more densely populated than others.]