The McConnel family were owners of a series of large
cotton spinning mills in
Ancoats in the city of
Manchester. The first mill, Sedgewick Mill, was built between 1818 and 1821 by the company of Messrs. McConnel & Kennedy under the chairmanship of James McConnel, William's father, and in partnership with
John Kennedy. James McConnel died in 1831 and three of his sons, Henry, James and William became partners in the business. By 1833, the
McConnel & Kennedy Mills were the largest importer of cotton from America, and Sedgwick Mill was one of the largest mills in operation in the United Kingdom. Henry retired from the business in 1860 and his brother James retired in 1861, leaving William as the sole owner of the mill. The outbreak of the
American Civil War in 1861 had a dramatic impact on McConnel & Kennedy. Raw cotton supplies from America were cut off, causing many Lancashire mills to sharply reduce production or close completely. Sedgwick Mill held large stocks of raw cotton and continued in limited production. By 1863, with the war continuing, McConnel was looking for other enterprises to diversify his interests away from cotton spinning. == Slate quarry and railway owner ==