Your own source demonstrates your distortions. The quote you just offered is Douglass saying that—after black Americans are no longer slaves—we must not tolerate allowing them to live lives of poverty and persecution like the Irish (which, let’s get real, is exactly what happened). Douglass explicitly rejected the idea that the Irish were “slaves” in the sense of treated like animals and property, with no more rights than an animal, like black American slaves.
Please read, at your pleasure:
In contrast to plight of poverty and oppression of the Irish:
"Negro-slavery consisted not in taking away a man’s property, but in making property of him, and in destroying his identity—in treating him as the beasts and creeping things. GOD had given the negro a conscience and a will, but his conscience was no monitor to him, for he had no power to exercise his will—his master decided for him not only what he should eat and what he should drink, what he should wear, when and to whom he should speak, how much he should work, how much and by whom he is to be punished—he not only decided all these things, but what is morally right and wrong.
“The slave must not even choose his wife, must marry and unmarry at the will of his tyrant, for the slave-holder had no compunction in separating man and wife, and thus putting as under what GOD had joined together.”
“the Irishman is poor, but he is not a slave. He may be in rags, but he is not a slave. He is still the master of his own body … The Irishman has not only the liberty to emigrate from his country, but he has liberty at home. He can write, and speak, and cooperate for the attainment of his rights and the redress of his wrongs.”