See C. H. Johnson, Utopian Communism in France: Cabet and the Icarians, 1839-1851 (1974)
The first European settlers here were a group of French Icarians who came from Nauvoo, Illinois in 1852; they established a community near Lake Icaria, north of Corning. The new state of Iowa gave the town of "Icaria" a corporate charter in 1860. This community was dedicated to the utopian principles of Etienne Cabet and the democratic principles of the American Revolution and the French Revolution; this small French-speaking community considered themselves to be very patriotic Americans. In the 1860s, the community split between "traditionalists" and "progressives" (the latter favored women's right to vote). The "progressives" left the original site and moved to a new location about three miles east of Corning's current location. Although the corporation formally dissolved in 1878, some continued to live in the communal dwellings until 1898, making this the longest-lasting Icarian colony in the United States. Eventually the community disbanded and merged into the general population. Displays and documents about the Icarian community can be found at the Icarian History Foundation office and in the Adams County offices, both in Corning. The former colony east of Corning is slowly being restored with the help of state and federal grants, and it will become a historical site; as of 2006, only a couple of partially-restored building and a very small cemetery (with grave markers inscribed in French) remain. Around the first weekend of June each year, Corning celebreates "Le Festival De L'Heritage Francais" in the French market.
Surveyors came to the current location of Corning in 1857, though the area was uninhabited (except by the Icarians) until 1869.
The first Adams County seat was established by act of the Iowa Legislature on January 12, 1853, at Quincy (now nonexistent) Iowa. The building was later used as a schoolhouse and in 1932 it was torn down. In November, 1872, the people voted to remove the courthouse from Quincy and locate the county seat in Corning. (As the story goes the vote was more an overtaking. A group of men took a team of horses with a wagon from Corning to Quincy.) The mayor's house was burned to the ground leaving the mayor/doctor for dead. Others that held documents in their homes were forced at gun point to surrender those documents. They were then taken to Corning were the new county seat was established.)
The first courthouse in Corning was built in 1872 at the present site of the Adams County courthouse. It was also a wood frame structure. The county jail was built in 1877 and used until 1955. This courthouse was destroyed by fire on February 1, 1888. Business buildings in Corning then served as temporary quarters for the county offices. On November 5, 1889, Adams County voters approved a bond issue not to exceed $30,000 for construction of a new courthouse. Money was to be raised by taxation of not to exceed 2 mills on the dollar each year. The new courthouse was dedicated on June 20, 1890. Barely 40 years later, this building, called one of the most modern in the country with its Queen Anne style of architecture, began to deteriorate and was razed in 1955.
There were 803 households out of which 24.3% had children under the age of 18 living with them, 46.9% were married couples living together, 6.7% had a female householder with no husband present, 4.1% were single, and 43.6% were non-families. 39.6% of all households were made up of individuals and 24.4% had someone living alone who was 65 years of age or older. The average household size was 2.14 and the average family size was 2.87.
In the city the population was spread out with 22.5% under the age of 18, 6.8% from 18 to 24, 24.5% from 25 to 44, 20.1% from 45 to 64, and 26.0% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 83.1 males. For every 100 females age 18 and over, there were 79.8 males.
The median income for a household in the city was $28,977, and the median income for a family was $45,227. Males had a median income of $26,667 versus $19,569 for females. The per capita income for the city was $15,836. About 5.0% of families and 7.5% of the population were below the poverty line, including 8.5% of those under age 18 and 9.7% of those age 65 or over.