Answer:
The line from "What to the Slave is the Fourth of July?" which supports Douglas' claim that the Fourth of July is not a cause worthy of celebration by all is:
O "Fellow-citizens, above your national, tumultuous joy, I hear the mournful wail of millions! whose chains, heavy and grievous yesterday, are, to-day, rendered more intolerable by the jubilee shouts that reach them."
Explanation:
The renowned American abolition advocate and civil rights fighter, Frederick Douglas delivered the above-named keynote address to the Rochester Ladies' Anti-Slavery Society on Independence Day July 5, 1852. Essentially, Douglas invited Americans to improve themselves. In addition, he stressed the need for citizens to exercise their voting franchise, because as someone said elsewhere, "voting is a great equalizer" for a just and egalitarian society.
