In 1840, Arthur married Rosalie, the daughter of Louis Demarie, a well known fur trader, who with his wife and family had come up the Chippewa River, in 1832. The same year, Arthur bought a Tavern from his brother-in-law Samuel Lamb, on the bank of the Red Cedar, at Dunnville, 12 miles from Menominee. In 1843, Arthur and Jeremiah Thomas with the help of Arthur's brothers Stephen and Daniel McCann began operating the Blue Mills, the first mill in the area, later known as the Badger State Mills, near present Lake Hallie. One of the workmen on the mill, named Sawyer, lost his wages to Arthur in a poker game. Sawyer accused Arthur of cheating and left. He later returned to the tavern and called Arthur outside where he shot and killed him.

Eau Claire Telegram, July 19, 1935
Arthur and Stephen McCann and Jeremiah Thomas, who established themselves in 1854, were the first actual settlers in Eau Claire, though Louis Demarie had traded with the Indians and together with his wife and five children had lived at the junction of the Eau Claire and the Chippewa, in the fall and winter of 1832-1833. A few miles away where the Blue Mills (Badger Mills or Lower Lake Hallie) Arthur McCann and Jeremiah Thomas put up a small sawmill in 1844, and in 1845 they and Stephen McCann constructed three buildings within the present municipal limits of Eau Claire, another being erected by Philo Stone and his brother Roswell, who came soon after. Arthur McCann later built a frame dwelling near the later site of Heart's Hotel (now the Y.M.C.A. site). He did not live long to enjoy it for in the following year he was shot at his own door by an employee named Sawyer.

Chippewa Falls Herald-Telegram, Aug 17, 1933
In 1843 Arthur McCann and J. C. Thomas erected a sawmill six miles south of the city and it was known as Blue Mills after "Blue Tom" Thomas. The mill changed hands once or twice and later was rebuilt and enlarged and called Badger Mills, being operated by the Badger State Lumber Company. Operation was discontinued in the 1890's because of a shortage of logs. The old Blue Mill pond is now Lake Hallie.

• Married: 1840 in Chippewa Falls, Chippewa Co., WI

1. Jackson McCann b: 1842