Dunning was born in Webster, New York on March 23, 1819. He had a common school education, and became a merchant and druggist by trade. He arrived in Wisconsin Territory in 1840, and settled in Dane County, first in Blooming Grove, where he farmed, and later moved into downtown Madison, reportedly because "the railroad built its tracks across their front yard." His original home in Blooming Grove is still standing. He was a delegate from Dane County to the May 1841 territorial Democratic Party meeting. In 1851 he was a member of both the WisconsinAgricultural Society and the Dane County Agricultural Society. For some years prior to 1877, he operated a sawmill on Clyde Creek in the nearby Town of Burke, which he either bought or built in 1841. As of 1858, he was a trustee of Madison's downtown Congregational Church. With his long-time partner Edwin Sumner, "Dunning and Sumner" on Pinckney Street in downtown Madison were retail and wholesale druggists, grocers, and sellers of products including "paints, oils, brushes, toilet articles, spectacles, etc." from 1868 or earlier until at least as late as 1892.
Public office
In 1852, Dunning was elected to the board of supervisors of the Town of Madison and served as its chairman and thus ex officio as a member of Dane County's County Board. He was elected County Treasurer of Dane county in 1854. When in 1856 the City of Madison was chartered as a separate entity, he was elected to its first Board of Supervisors. In 1873 he was appointed to the state's visiting committee on charitable and penal institutions by Gov. Cadwallader C. Washburn. In that same year he was elected to the Assembly's 2nd Dane County district as the candidate of the Reform Party with 1,388 votes, against 995 for former state senatorClement Warner, a Republican. He was assigned to the joint committee on charitable and penal institutions. He was not a candidate for re-election in 1874, and was succeeded by Democrat Silas U. Pinney. He served again on the Dane County Board of Supervisors for the 1878–1879 term from the 2ndWard of Madison. From 1879 to 1893 he was a member of the Wisconsin Fish Commission; from 1887 to 1893 he served as president of that body. In the spring of 1889 he was elected to the executive committee of the American Fisheries Society. In May 1893 it was announced that he had retired from business "to take life easy". He died on September 10, 1900 after suffering from paralysis for a year, and he is buried in Madison's Forest Hill Cemetery.
