Like many Long Island communities at the time, Rockville Centre's population included a considerable number of supporters of the Ku Klux Klan during the 1920s. When the white supremacist organization placed a wreath at the town's memorial to its war dead in 1923, the American Legion removed it in protest, but the city police received so many calls of complaint in response that they were forced to replace the wreath. In the late 1960s, the village of Rockville Centre received a stinging rebuke for its failure to maintain public housing units primarily inhabited by African-Americans. A report from Nassau County's Human Rights Commission stated Rockville Centre was "at best indifferent to, if not actually in favor of, Negro removal." Martin Luther King Jr. visited Rockville Centre in 1968, where he addressed a large audience at South Side Junior High School on March 26, 1968.