 The dam was built across the Santee River to generate hydroelectric power for rural electrification, one of the major infrastructure projects initiated under President Franklin D. Roosevelt's New Deal federal investments during the Great Depression.Lake Marion and the Santee Dam were part of the Santee-Cooper Hydroelectric and Navigation Project.Two notable court cases in Clarendon County in the mid-20th century were part of challenges by the Civil Rights Movement to racial segregation of public facilities; these cases related to segregated public schools.