The first Plymouth County Fair to be held at the Le Mars fairgrounds was held on September 8-10, 1941.After outgrowing the fair headquarters in Merrill, the Plymouth County 4-H and Agricultural Society made its move to Le Mar, the same site where the fair is held today.On May 16, 1941 at a special meeting held at the Union Hotel, the Le Mars Chamber of Commerce unanimously voted to purchase the twenty acres to be used for the promotion of agriculture and 4-H club work in Plymouth County until an agricultural society could be organized by June 1, 1944.The total purchase price was $3,000.They voted to authorize county 4-H clubs to erect buildings and make improvements.The girls used the county club for their exhibits and the boys will have tents for entries that cannot be accommodated in one building, while other features of events were held at the Municipal Park in town.In 1947 they put up a block building and two livestock barns, one for swine and one for calves, at the cost of $950.The show was growing rapidly.More room was needed for Home Economic exhibits.In 1948 a loud speaker was installed and the sixth livestock building was erected.At the 1949 fair, a record three day attendance was set at 15,000 people.Each year the fair continued to grow with new buildings, food stands, and bigger and better entertainment.In 1956 eleven additional acres were purchased for $1,000 per acre.An additional swine barn was built with a scale under the roof, seating space for 100 people, and a show ring all combined for $7,004.In 1964 the 4-H and Ag Committee was given the okay to build a 4-H Food Stand.This would be a joint boys and girls club stand.In that year the Fairboard bought what was known as the Girl’s 4-H Building for $550.The north end was used by KLEM radio station.In 1966 the covered rest area was created.In the mid 70’s the Pioneer Village was developed.This included adding buildings which would take until the mid 90’s to complete.A stage and entertainment was added to the village to enhance the atmosphere.Since then many buildings have undergone renovation or have been re-built.Additional livestock buildings have been built to accommodate the ever changing needs of the agricultural industry. A new commercial exhibit building, Hall of 15, was constructed an opened for the 2015 fair. It sits next to Century Hall. The Plymouth County Fair celebrated its 75th anniversary at the 2016 fair.The fair is proud to continue to be one of the largest county fairs in Iowa and the Plymouth County 4-H program has approximately 450 members which rank 3rd in the state for enrollment. There is currently a FFA chapter in all five public schools in the county.