August 21, 1858, brought the first of the famous Lincoln-Douglas debates in Illinois between Abraham Lincoln and Stephen Douglas, both running for the U.S. Senate. There were seven debates in all, the first in the town of Ottawa, and they set the prairies ablaze as people flocked by the thousands to see the tall, lanky Lincoln match his wits with the short, square-shouldered, broad-chested Douglas.
The debates centered on the question of whether slavery should be allowed to expand into U.S. territories. Douglans, a famous sitting senator, argued that the people of each territory should decide whether to allow slavery in their land. Lincoln opposed any expansion of slavery, which he regarded as a "moral, social, and political wrong." In the final debate Lincoln aruged:
That is the issue that will continue in this country when these poor tongues of Judge Douglas and myself shall be silent. It is the eternal struggle between two principles. The one is the common right of humanity, and the other the divine right of kings. It is the same spirit that says, "You will toil and work and earn bread, and I'll eat it." No matter in what shape it comes, whether from the mouth of a king who seeks to bestride the people of his own nation and live by the fruit of their labor, or from one race of men as an apology for enslaving another race, it is the same tyrannical principle.
Newspapers across the country followed the debates, and although Lincoln lost the Senate race to Douglas, his careful arguments helped turn him from a relatively obscure prairie lawyer into a national figure. The Lincoln-Douglas debates were the most important since the ratification of the Constitution. Lincoln showed a mastery of law, philosophy, and history that raised him above not only Douglas but ultimately every other stateman of the age.
(The American Patriot Almanac)