The Negro population of New York City has had a history similar to that of other Northern cities. Beginning with a small body of slaves, it has since had its problems growing out of the presence of an increasing number of Negroes in the midst of the environing white group. In 1629, The Dutch West India Company pledged itself to furnish slaves to the Colonists of New Amsterdam.[37] A similar resolution was passed by the colony council in 1648[38] and by 1664 slavery had become of sufficient importance to receive legislative regulation in the Duke of York Code.[39] Both by further importations and by natural increase the Negro population grew until in 1704 it numbered about 1,500; in 1741 it was estimated at about 2,000, and in 1757 about 3,000. Beginning with the first Federal Census of 1790 there was an increase shown by each census except those of 1820 for Brooklyn and of 1850 and 1860 for other parts of New York City, mainly Manhattan. The figures show a striking contrast in growth between Brooklyn and the other parts of New York City as now constituted, exclusive of Brooklyn. The former had a comparatively small Negro population until after 1860, but from 1790 the Negro population although small increased steadily, except the one decade between 1810 and 1820. This was a decrease of only 92 or 4.9 per cent of a population less than 2,000. Only one increase, from 1800 to 1810, was less than 13 per cent. Beginning with 5,915 at the Federal census of 1790, the Negro population of the other parts of New York City has shown a high per cent of increase in numbers, above 15 per cent, at eight of the twelve succeeding censuses, and 8.1 per cent and 5.5 per cent at two others. The decreases from 1840 to 1850, 13.2 per cent, and from 1850 to 1860, 7.5 per cent, were probably due to the unfavorable sentiment against the Negroes which arose during the abolition agitation of these periods and which had its effect on the Negro's movements to and from the city. The small increase from 1860 to 1870, 5.5 per cent, was very probably the result of the same causes--of the Civil War disturbances and the New York Draft riots, which deterred Negroes from coming to New York City and sent many Negro residents away.[40] The figures for Manhattan show a similar trend at each census. However, except the periods noted above, there has been a general trend toward increase in both Manhattan and Brooklyn. The Negro population has become a smaller and smaller part of the total population from decade to decade since 1810, but this is because the several streams of foreign immigrants have been large and not because the increase of the Negro population has been small. Table VIII, which follows, shows the growth of the total and the Negro populations, and brings the full figures to view: TABLE VIII. TOTAL AND NEGRO POPULATION OF NEW YORK CITY, AS AT PRESENT CONSTITUTED, 1704-1910.[A]