[Sidenote: Effects of the Ordinance of 1787.] By the famous Ordinance of 1787, to which we shall again have occasion to refer, negro slavery had been forever prohibited to the north of the Ohio river, so that, in spite of the wishes of her early settlers, Illinois was obliged to enter the Union as a free state. But in 1820 Missouri was admitted as a slave state, and this turned the stream of southern migration aside from Illinois to Missouri. These emigrants, to whom slaveholding was a mark of social distinction, preferred to go where they could own slaves. About the same time settlers from New England and New York, moving along the southern border of Michigan and the northern borders of Ohio and Indiana, began pouring into the northern part of Illinois. These new-comers did not find the representative county system adequate for their needs, and they demanded township government. A memorable political struggle ensued between the northern and southern halves of the state, ending in 1848 with the adoption of a new constitution. It was provided that the legislature should enact a general law for the political organization of townships, under which any county might act whenever a majority of its voters should so determine.[10] This was introducing the principle of local option, and in accordance therewith township governments with town-meetings were at once introduced in the northern counties of the state, while the southern counties kept on in the old way. Now comes the most interesting part of the story. The two systems being thus brought into immediate contact in the same state, with free choice between them left to the people, the northern system has slowly but steadily supplanted the southern system, until at the present day only one fifth part of the counties in Illinois remain without township government. [Footnote 10: Shaw, _Local Government if Illinois_, J. H. U. Studies, I., iii.] [Sidenote: Intense vitality of the township system.] This example shows the intense vitality of the township system. It is the kind of government that people are sure to prefer when they have tried it under favourable conditions. In the West the hostile conditions against which it has to contend are either the recent existence of negro slavery and the ingrained prejudice in favour of the Virginia method, as in Missouri; or simply the sparseness of population, as in Nebraska. Time will evidently remove the latter obstacle, and probably the former also. It is very significant that in Missouri, which began so lately as 1879 to erect township governments under a local option law similar to that of Illinois, the process has already extended over about one sixth part of the state; and in Nebraska, where the same process began in 1883, it has covered nearly one third of the organized counties of the state.