In the past, what events served as threats to America’s national identity? Explain why.

I recommend reading a book named ‘The Challenges to America's National Identity’  is a treatise by political scientist and historian Samuel P. Huntington. The book attempts to understand the nature of American identity and the challenges it will face in the future.

on june 23, 1972, the president signed title ix of the education amendments of 1972, 20 u.s.c. into law. title ix is a comprehensive federal law that prohibits discrimination on the basis of sex in any federally funded education program or activity.