In the postwar period, African-American veterans and others began to press for improved civil rights. There was high resistance from many whites, leading to outbreaks of violence and other forms of intimidation. Despite this, mature men with families were among those who joined the NAACP and later such groups as CORE and SNCC. Given the repressed state of its black population, Mississippi was a center of the Civil Rights Movement. In 1954 the US Supreme Court ruled in "Brown v. Board of Education" that segregated public education was unconstitutional. In reaction the state set up the Mississippi State Sovereignty Commission, ostensibly to market its advantages. This tax-supported group began to spy on state citizens, identifying professionals such as teachers as activists, and sharing data on persons' activities with the White Citizens Councils formed in many cities and towns in this period. Whites used economic intimidation to suppress activism, firing people from jobs, evicting them from rental properties, refusing loans, etc. The state's activities captured the national stage in 1963 and 1964. Few white leaders in the state supported the effort to secure voting and exercise of other civil rights for African Americans.