When Illinois was admitted to the Union in 1818, all the organized counties lay to the south of the projected national road between Terre Haute and Alton, hence well within the sphere of surrounding Southern influences. The society of Illinois was at this time predominantly Southern in its origin and characteristics.[303] Social life and political thought were shaped by Southern life and Southern thought. Whatever points of contact there were with the outside world were with the Southern world. The movement to make Illinois a slave State was motived by the desire to accelerate immigration from the South. But people had already begun to come into the State who were not of Southern origin, and who succeeded in deflecting the current of Illinois politics at this critical juncture. The fertile river bottoms and intervening prairies of southern Illinois no longer sufficed. The new comers were impelled toward the great, undulating prairies which expand above the 39th parallel. The rise of new counties marks the volume of this immigration;[304] the attitude of the older settlers toward it, fixes sufficiently its general social character. This was the beginning of the "Yankee" invasion, New York and Pennsylvania furnishing the vanguard. As the northern prairies became accessible by the lake route and the stage roads, New England and New York poured a steady stream of homeseekers into the Commonwealth. By the middle of the century, this Northern immigration had begun to inundate the northern counties and to overflow into the interior, where it met and mingled with the counter-current. These Yankee settlers were viewed with hostility, not unmixed with contempt, by those whose culture and standards of taste had been formed south of Mason and Dixon's line.[305] This sectional antagonism was strengthened by the rapid commercial advance of northern Illinois. Yankee enterprise and thrift worked wonders in a decade. Governor Ford, all of whose earlier associations were with the people of southern Illinois, writing about the middle of the century, admits that although the settlers in the southern part of the State were twenty, thirty, forty, and fifty years in advance, on the score of age, they were ten years behind in point of wealth and all the appliances of a higher civilization.[306] The completion of the canal between Lake Michigan and the Illinois River, however much it might contribute to the general welfare of the State, seemed likely to profit the northern rather than the southern portion. It had been opposed at the outset by Southerners, who argued soberly that it would flood the State with Yankees;[307] and at every stage in its progress it had encountered Southern obstruction, though the grounds for this opposition were more wisely chosen.