The Fair Started in 1841 as the Herkimer County Agricultural Society and apparently traveled from village to village and became located at the Herkimer Site (which is now the Herkimer Thruway interchange)sometime in the early 1900,s. The County Fair at that time had a race track and grandstand which was destroyed by fire .The County Fair was incorporated and was held annually after moving to Frankfort in 1950 and then moved to a permanent site on Cementery Hill in Frankfort in 1958 after purchasing the Slocum Farm. The first fair was held in 1958 using the existed farm buildings and plenty of tents and Gillette Shows for the 4 Day event with an attendance of 14,000.

The Fair continued to grow and presently sits on 26 acres and now has 10 permanent buildings as well a permanent bathroom and shower facility , a Horse Corral and 1850 Aluminum Bleacher Seating surrounding the event show ring. The Fairgrounds is the Home of Several events including the Great American Irishfest held end of July, The New York State Trappers Convention held end of August and the New York State Good Sam Samboree first part of July. Other events include Hamfests, Rabbit Shows , Motor Home Rallies and Music Fests.

Presently the Fair attendance exceeds 60,000 in the 6 Day fair with Gillette Shows still an important part of the fair.