• US Senator from Illinois 1847 – 1861
• U.S. House of Representatives from Illinois's 5th district 1843 – 1847
• Associate Justice of the Supreme Court of Illinois 1841 – 1843

• 7th Secretary of State of Illinois 1840 – 1841

  Douglas's reputation was a daunting one. As James G. Blaine later wrote:

He [Douglas] was everywhere known as a debater of singular skill. His mind was fertile in resources. He was master of logic. No man perceived more quickly than he the strength or the weakness of an argument, and no one excelled him in the use of sophistry and fallacy. Where he could not elucidate a point to his own advantage, he would fatally becloud it for his opponent. In that peculiar style of debate, which, in its intensity, resembles a physical contest, he had no equal. He spoke with extraordinary readiness. There was no halting in his phrase. He used good English, terse, vigorous, pointed. He disregarded the adornments of rhetoric,—rarely used a simile. He was utterly destitute of humor, and had slight appreciation of wit. He never cited historical precedents except from the domain of American politics. Inside that field his knowledge was comprehensive, minute, critical. Beyond it his learning was limited. He was not a reader. His recreations were not in literature. In the whole range of his voluminous speaking it would be difficult to find either a line of poetry or a classical allusion. But he was by nature an orator; and by long practice a debater. He could lead a crowd almost irresistibly to his own conclusions. He could, if he wished, incite a mob to desperate deeds. He was, in short, an able, audacious, almost unconquerable opponent in public discussion.