Presidential historian Jon Meacham argued on MS NOW that America did not become a "multiracial, multiethnic democracy" until 1965 ahead of its 250th birthday.
https://www.foxnews.com/media/america-wasnt-really-founded-until-1965-ms-now-guest-historian-argues-ahead-250th-birthday
https://www.foxnews.com/media/america-wasnt-really-founded-until-1965-ms-now-guest-historian-argues-ahead-250th-birthday