The aggregate amount of the postage received at the different post-offices must always depend, in a greater or less degree, upon the extent and frequency of the mail transportation by which such offices are supplied, and the rates of postage charged, as well as upon the number, education, character and occupation of the population within the delivery of such offices. Other causes, some of them local or temporary, may at times affect the revenue of an office, but only the population of the neighborhood, the frequency and extent of the transportation service, and the general rates of letter postage, will be here considered. The first census under the authority of the United States was taken in 1790; probably in July and August of that year. In that portion of New York lying west of the old Massachusetts preemption line it was taken by General Amos Hall, as Deputy Marshal, and an abstract of his list or census-roll is given in Turner's "History of Phelps and Gorham's Purchase." The number of heads of families then residing west of Genesee River, and named in that list, was 24; but it is probable that the deputy marshal did not visit this locality, as neither Winney the Indian trader, nor Johnston the Indian agent and interpreter, is named; although it is probable that both of them resided here. Winney, it is quite certain, was here in 1791, and it is supposed came about 1784. The whole population west of the Massachusetts preemption line, which was a line drawn due north and south across the State, passing through Seneca Lake and about two miles east of Geneva, as given by Turner from General Hall's census-roll, was 1,084, as follows: males, 728; females, 340; free blacks, 7; slaves, 9. In the State census report of 1853, the population of Ontario County in 1790 (which county then embraced all that territory) is stated at 1,075. The difference between the two statements is caused by the omission of the slaves from the latter statement. In 1800 the population of the same territory (then the Counties of Ontario and Steuben) was 15,359 free persons and 79 slaves. In 1808 the County of Niagara (embracing the present counties of Niagara and Erie) was organized, and its population in 1810 was 6,132. Of these 1,465 were inhabitants of the present County of Niagara, and 4,667 of the present County of Erie. There were then in the county 8 slaves, which number should probably be added to the aggregate above stated. In 1820 the population of Niagara County was 18,156, of which 10,834 were inhabitants of the present County of Erie. There were then 15 slaves in the whole County of Niagara. In 1821, the County of Erie was organized with its present boundaries. Its population at each census since has been as follows, viz: 1825, 24,316; 1830, 35,719; 1835, 57,594; 1840, 62,465; 1845, 78,635; 1850, 100,993; 1855, 132,331; and 1860, 141,791.