Marsh Creek State Park is very well known as a recreational facility and provider of water management but before the dam and park were built Marsh Creek flourished with large fields, homes and farms. A community known as Millford Mills stood strong as the community of farms and mills provided much produce, paper and other important products to the Chester County area. With properties dating as far back as the 1800's the Marsh Creek Valley slowly managed to disappear from the memories of many residents of the county because the PA Department of Conservation and Natural Resources sought this area to be a good place to create a reservoir to raise the levels of fresh drinking water to the county. A dam was to be built to not only provide fresh water but to also help with issues like flooding and droughts that had been frequently occurring within Chester County. In order to make capture the attention of residents to help promote the dam the collaboration of the Commonwealth, the Chester County Water Resources Authority claimed that the reservoir would also provide recreational services as well.

     Even though the dam was officially completed by 1975 the plan to create the park dated back to as early as 1955. As the Chester County Commissioners board surveyed the Marsh Creek Valley to gain more understanding to how a dam would benefit not only Uwchlan township but also the townships around it  seeing as how it would be a new headwaters to the Brandywine River. By the late 1960's all the property that would need to be cleared out was bought out. Anyone who sold their property to the county was to move as soon as possible in order to start creating the dam.

    As stated before the dam, through the county's eyes, would hold an amazing amount of opportunities. The dam would not only boost the potential of the Brandywine watershed for the county's watershed but it would also provide many recreational options for residents. The surrounding area of Marsh Creek lake would be open for horseback riding, hiking, biking and picnic areas. The lake itself would flourish with incoming fresh water fish and therefore be open for fishing to anyone with a license. Boats would be allowed to however due to the lakes original purpose; fresh drinking water, large motor boats would not be permitted in case of a potential pollution situation. Finally the dam would also provide electricity to it's neighboring residents with hydroelectricity. 

    In 1970 construction began to take place, residents of Millford Mills and the surrounding community were to relocate themselves in order to allow workers to clear out the area. By the time the dam was built in 1973 it took about three years to fill Marsh Creek Lake. Many people did not realize what was happening to the area until construction was taking place. What use to be a place of great natural beauty turned into an eye sore as some people refused to visit the area. Kids who owned dirt bikes raced and rode through the reservoir until the dam began to be filled. Today a wooden plaque thanking several different departments for making the park possible is located at the dam itself as visitors walk along the path on top of the dam.