The population of Illinois, in 1810, was 12,282, and in 1860, 1,711,951; the ratio of increase from 1810 to 1860 being 13,838.70. (Table 1, Cens. 1860.) The population of Missouri in 1810, was 20,845, and in 1860, 1,182,012; the ratio of increase from 1810 to 1860 being 5,570.48. (Ib.) The rank of Missouri in 1810 was 22, and of Illinois 23. The rank of Missouri in 1860 was 8, and of Illinois, 4. AREA.--The area of Missouri is 67,380 square miles, being the 4th in rank, as to area, of all the States. The area of Illinois is 55,405 square miles, ranking the 10th. Missouri, then, has 11,875 more square miles than Illinois. This excess is greater by 749 square miles than the aggregate area of Massachusetts, Delaware, and Rhode Island, containing in 1860 a population of 1,517,902. The population of Missouri per square mile in 1810 exceeded that of Illinois .08; but, in 1860, the population of Missouri per square mile was 17.54, ranking the 22d, and that of Illinois, 30.90, ranking the 13th. Illinois, with her ratio to the square mile and the area of Missouri, would have had in 1860 a population of 2,082,042; and Missouri, with her ratio and the area of Illinois, would have had in 1860 a population of 971,803, making a difference in favor of Illinois of 1,110,239 instead of 529,939. The absolute increase of population of Illinois per square mile from 1850 to 1860 was 15.54, and of Missouri 7.43, Illinois ranking the 6th in this ratio and Missouri the 14th. These facts prove the vast advantages which Missouri possessed in her larger area as compared with Illinois. But Missouri in 1810, we have seen, had nearly double the population of Illinois. Now, reversing their numbers in 1810, the ratio of increase of each remaining the same, the population of Illinois in 1860 would have been 2,905,014, and of Missouri, 696,983. If we bring the greater area of Missouri as an element into this calculation, the population of Illinois in 1860 would have exceeded that of Missouri more than two millions and a half. MINES.--By Census Tables, 9, 10, 13, and 14, Missouri produced, in 1860, pig iron of the value of $575,000; Illinois, none. Bar and rolled iron--Missouri, $535,000; Illinois, none. Lead--Missouri, $356,660; Illinois, $72,953. Coal--Missouri, $8,200; Illinois, $964,187. Copper--Missouri, $6,000; Illinois, none. As to mines, then, Missouri has a decided advantage over Illinois. Indeed, the iron mountains of Missouri are unsurpassed in the world. That Illinois approaches so near to Missouri in mineral products, is owing to her railroads and canals, and not to equal natural advantages. The number of miles of railroad in operation in 1860 was, 2,868 in Illinois, and 817 in Missouri; of canals, Illinois, 102 miles; Missouri, none. (Tables 38, 39.) But if Missouri had been a Free State, she would have at least equalled Illinois in internal improvements, and the Pacific Railroad would have long since united San Francisco, St. Louis, and Chicago.