The Warren County Agricultural Society was organized December 1, 1849. Previous to this there were several exhibitions at Lebanon of agricultural and mechanical products called fairs. One of these was held in Osborn’s Grove, November 15, 1839. The first annual fair of the society was held on the farm of John Osborn, then one-half mile east of Lebanon where Colony Square Shopping Center is now located, on September 26 and 27, 1850, and was deemed a respectable exhibition. The total receipts of the society reported after the close of this fair, were $354.50, of which sum $214 had been received from membership fees, $25 were donated by the Shaker Society and $115.50 were received from the County Treasury.

The second annual fair was held on the same grounds, September 9 and 10, 1851. In 1852 the society leased ten acres of ground from Robert G. Corwin, Esq., for fair purposes, and built a tight board fence, eight feet high, around five acres of the same, and erected within the enclosure a frame building, eighty feet by twenty-four feet. The first fair on these grounds, which constituted a part of the present fair grounds, was held on September 22 and 23, 1852, and was more largely attended than either preceding exhibition. An Admission fee of 15 cents was charged for all persons not a member of the society.

Source: Beer’s 1882 Warren County History