What congressional action did the Supreme Court use as their foundation for opposing sexual harassment?

The answer is Title VII.

Explanation:

The Civil Rights Act of 1964 is considered a landmark concerning civil rights and labor law. This act was established in the United States and it outlaws any kind of discrimination that is based on aspects related to race, color, religion or sex.

It also prohibits racial segregation in places like schools, as well as this is applied in terms of employment and public accommodations. Congress imposed its authority to establish and legislate according to some parts related to the United States Constitution, its duty to provide equal protection for all citizens according to the Fourteenth Amendment.