The important law passed in the United States in 1964 to outlaw discrimination was the Civil Rights Act. Signed into law by President Lyndon B. Johnson, this landmark legislation aimed to eliminate discrimination based on race, color, religion, sex, or national origin. It addressed segregation in schools, public places, and employment, providing a legal foundation for the civil rights movement's efforts to achieve equality. The Civil Rights Act has had a lasting impact on American society, promoting social justice and civil liberties.