Time and again he was commended for his services and declined promotion to higher rank in other arms of the service.

"He loved the scarlet facings of the artillery, and there was something in the ranking of batteries and the power of cannon," writes Thompson, "that was akin to the workings of his own mind." In 1862 he was married to his cousin, Miss Emma Dean, of Detroit, who still lives in Washington with their daughter, an only child.

Mrs.
Powell was often his companion in the army and early Western journeys.
Upon the return of Powell to civil life in 1865 he was tendered a nomination to a lucrative political office in Du Page County, Illinois, and at the same time he was offered the chair of geology in the Wesleyan University, a struggling Methodist College at Bloomington, Illinois.
There was no hesitation on his part.

He declined the political honour and its emoluments and accepted the professorship, which he retained two years.

At the session of the Illinois Legislature in 1867 a bill was passed, largely through his effort, creating a professorship of geology and natural history in the State Normal University at Normal, Illinois, with a salary of fifteen hundred dollars and an appropriation of one thousand dollars annually to increase the geological and zoological collections.