In the early history of Illinois, negro slavery was a bone of contention between men of Northern and of Southern antecedents.  When Illinois was admitted as a State, there were over seven hundred negroes held in servitude.  In spite of the Ordinance of 1787, Illinois was practically a slave Territory.  There were, to be sure, stalwart opponents of slavery even among those who had come from slave-holding communities; but taken in the large, public opinion in the Territory sanctioned negro slavery as it existed under a loose system of indenture.[309] Even the Constitution of 1818, under which Illinois came into the Union as a free State, continued the old system of indenture with slight modification.[310]

It was in the famous contest over the proposed constitutional convention of 1824 that the influence of Northern opinion respecting slavery was first felt.  The contest had narrowed down to a struggle between those who desired a convention in order to draft a constitution legalizing slavery and those who, from policy or principle, were opposed to slavery in Illinois.  Men of Southern birth were, it is true, among the most aggressive leaders of the anti-convention forces, but the decisive votes against the convention were cast in the seven counties recently organized, in which there was a strong Northern element.[311]

This contest ended, the anti-slavery sentiment evaporated.  The “Black Laws” continued in force.  Little or no interest was manifested in the fate of indentured black servants, who were to all intents and purposes as much slaves as their southern kindred.  The leaven of Abolitionism worked slowly in Illinois society.  By an almost unanimous vote, the General Assembly adopted joint resolutions in 1837 which condemned Abolitionism as “more productive of evil than of moral and political good.”  There were then not a half-dozen anti-slavery societies in the State, and these soon learned to confine their labors to central and northern Illinois, abandoning Egypt as hopelessly inaccessible to the light.[312]

The issues raised by the Mexican War and the prospective acquisition of new territory, materially changed the temper of northern Illinois.  Moreover, in the later forties a tide of immigration from the northeastern States, augmented by Germans who came in increasing numbers after the European agitation of 1848, was filling the northernmost counties with men and women who held positive convictions on the question of slavery extension.  These transplanted New Englanders were outspoken advocates of the Wilmot Proviso.  When they were asked to vote upon that article of the Constitution of 1848 which proposed to prevent the immigration of free negroes, the fourteen northern counties voted no, only to find themselves outvoted two to one.[313] A new factor had appeared in Illinois politics.