His main business was in cotton but he also engaged J. Edgar Thomson to design the Augusta Canal, in order to run his mills and had started a law firm with politician George W. Crawford.
However, in 1822, William Cumming had gained a nationally notorious reputation when he fought George McDuffie in a duel, on two separate occasions which were believed to have been politically motivated.
John Forsythe, the U.S. Secretary of State at the time, had appointed Henry Cumming to be the U.S. Minister to Spain; mainly he would have served as an attaché at the American Legation.
The 1840s economic situation in the South was precarious for multiple reasons, one definite factor for Augusta to be in bad shape during the period was the depression of 1837; which consequently had significantly lowered the cotton prices.
To overcome the public sentiment and doubt: Cumming showed his confidence in the canal project by donating the necessary funds to carry out the initial survey for the site.
By the 1850s, the canal had allowed for a sawmill, a gristmill, a textile mill, and other types of factories to erect in Augusta; this proved that Cumming's vision had some validity behind it.
His strong sense of civic duty had borne many fruits in Georgia, this includes the Augusta Canal—which is his crowned public service achievement.
Between the success of the canal and in his business, Cumming gained the confidence of his local brethren and was able to be far more persuasive in his later attempts of civil services.
He noted that when he had the intention to write love letters to his "sweetheart," he found that "he just wrote about himself" and that he tended to "display accomplishments in fine style" rather than trying to "romance" Miss Bryan.