Intelligence test scores and diplomas as requirements for employment, the court ruled, are not in themselves illegal under Title VII. The court overturned the rulings of the lower courts, deciding in favor of Griggs. Supreme Court finally heard the case in late 1970, and Justice Burger’s opinion took several months to draft. After the case moved beyond the district level, the Fourth Circuit Court of Appeals ruled that the intelligence tests administered by Duke Power did not reflect any discriminatory intent and thus were not unlawful under Title VII of the Civil Rights Act. A federal district court ruled in favor of Duke Power on the ground that Duke Power’s policy of overt racial discrimination – to wit, racial segregation – had ceased. The plaintiffs’ argument was that Title VII of the Civil Rights Act, which forbade race-based discrimination in employment, prohibited employer-administered tests that could have an exclusionary effect African-Americans. The tests thus put African-Americans at a disadvantage to whites in Duke Power’s hiring and advancement, and this disadvantage prompted the plaintiffs’ suit. The plaintiffs, Duke Power, and all courts that heard the case agreed that whites fared better than African-Americans on these intelligence tests. The scores that Duke Power required on each test were national median scores for high school graduates. Later that year, Duke Power began allowing non-high-school graduates to transfer from Labor to other departments if they could register sufficient scores on the Wonderlic Test, which rates general mental ability, and the Bennett Mechanical Comprehension Test, which is intended to predict job performance in mechanical fields. (The other departments of Duke Power included Maintenance, Operations, and Laboratory.) In 1965, when the Civil Rights Act went into effect, this requirement was expanded to block transfers from Labor to other departments by employees who had not graduated high school. In 1955, Duke Power instituted a high school diploma requirement for initial hiring in any department except Labor. Before the passage of the Civil Rights Act, Duke Power discriminated against African-Americans in hiring and promotion, restricting them to the company’s Labor department. The case originated in a lawsuit filed by Willie Griggs and twelve other African-American employees of Duke Power’s Dan River hydroelectric plant in Draper, North Carolina. Chief Justice Warren Burger delivered the Court’s opinion that employers can use intelligence tests only if "they are demonstrably a reasonable measure of job performance." The court ruled unanimously against the intelligence testing practices of the Duke Power Company. It concerned the legality, under Title VII of the Civil Rights Act of 1964, of high school diplomas and intelligence test scores as prerequisites for employment. Duke Power Company was a landmark employment discrimination case decided by the U.S.