What was Frederick Douglass’s most important advice for black Americans and other oppressed classes, and how does this advice resonate in American culture today?

Frederick Douglass provided strong guiding principles for black Americans and other minorities oppressed under traditional white European values. It seems impossible to give an unequivocal response about what piece of his advice was “most important,” as opinions and societal values change over time. Reasonable claims can be made that Douglass’s overall message has endured, though, and that America needs to acknowledge that oppression is a reality and every man, woman, and child deserves equal rights in American society.
Many civil rights leaders invoke Frederick Douglass’s message as they raise awareness about oppression in America today. President Barack Obama has expressed his admiration for Douglass, and how Douglass helped lay the groundwork that resulted in Obama’s position as the first black American President. Although a black American currently holds the country’s highest elected political office, many still argue that racial and gendered minorities still lack equal rights and opportunities. Douglass's message resonates through demonstrations and protests across the current American cultural landscape. A notable ongoing example can be found in the Black Lives Matter movement to protest the systematic inequality and racism black Americans face on a routine basis. Douglass’s advice is indeed timeless, but it is troubling that his vision for equality is still a long way from the country’s current reality.
https://www.history.com/topics/black-history/frederick-douglass