Why do Blacks Pledge to the flag, and cross their heart for the National Anthem?

With the many discussions of protesting the NFL, talking about whether or not people are disrespecting the flag, and the military, it being deemed as not patriotic if you don't stand and salute the National Anthem etc, it has me thinking about the origin of the flag's Pledge of Allegiance, and the National Anthem. I'm really interested in why Blacks EVER stood for the flag and the anthem? How does either one represent you? I'm sure people have various philosophical reasons, and that's why it's this week's topic. Why do Blacks Pledge Allegiance to the American Flag, and cross their and recite the National Anthem? "Darryel's Daily Dialogue....where positive words, manifest positive action."