Cool Spring Park was founded in 1877, as excess land from the development of the Cool Spring Reservoir. It was under the jurisdiction of the Wilmington Water Department until it became part of the Parks Department in 1967. Cool Spring was named for the Springs found in the area and was the name of the nearby home owned by Ceasar A. Rodney, nephew of Ceasar Rodney who was a signer of the Declaration of Independence.
The building of the reservoir and pumphouse, between 1873 and 77, allowed the city to meet the needs of the rapidly growing city. It also allowed the old city water basin, at the site of today’s Rodney Square to close.
Cool Spring Park was the site of the annual Wilmington Flower Market from the 1920’s to the 1950’s. Today the park has variety of trees because a new one was added each year as part of the Flower Market. The park landscaping has changed over the years, and in the early 20th Century, it included a cloverleaf of shallow ponds.