There is a long section in Darwin's work when he considers the evidence, pro and con, about whether the negro was a separate species. Despite the almost universal racism of the times, affecting Englishmen and Americans (and probably the rest of the world too), Darwin refused to conclude that the negro was of a different species from the white man. In this, he showed remarkable intellectual fortitude, and his work can indeed be given some credit for our currently enlightened views on race. This is a much more defensable position than blaming Darwin -- by all accounts a gentle soul -- for the evils of Hitler.
And why would he have any trouble discerning that? Nearly 2000 years before this story reaffirmed that man was man.(even eunuchs)
Act 8:27 And he arose and went: and, behold, a man of Ethiopia, an eunuch of great authority under Candace queen of the Ethiopians, who had the charge of all her treasure, and had come to Jerusalem for to worship,
Act 8:28 Was returning, and sitting in his chariot read Esaias the prophet.
Act 8:29 Then the Spirit said unto Philip, Go near, and join thyself to this chariot.
Act 8:30 And Philip ran thither to [him], and heard him read the prophet Esaias, and said, Understandest thou what thou readest?
Act 8:31 And he said, How can I, except some man should guide me? And he desired Philip that he would come up and sit with him.
Act 8:32 The place of the scripture which he read was this, He was led as a sheep to the slaughter; and like a lamb dumb before his shearer, so opened he not his mouth:
Act 8:33 In his humiliation his judgment was taken away: and who shall declare his generation? for his life is taken from the earth.
Act 8:34 And the eunuch answered Philip, and said, I pray thee, of whom speaketh the prophet this? of himself, or of some other man?
Act 8:35 Then Philip opened his mouth, and began at the same scripture, and preached unto him Jesus.
Act 8:36 And as they went on [their] way, they came unto a certain water: and the eunuch said, See, [here is] water; what doth hinder me to be baptized?
Act 8:37 And Philip said, If thou believest with all thine heart, thou mayest. And he answered and said, I believe that Jesus Christ is the Son of God.
Act 8:38 And he commanded the chariot to stand still: and they went down both into the water, both Philip and the eunuch; and he baptized him.
Act 8:39 And when they were come up out of the water, the Spirit of the Lord caught away Philip, that the eunuch saw him no more: and he went on his way rejoicing.
Nonsense. The abolition movement had started long before Darwin ever published the Origin. In addition, England had been promoting abolition for decades before the Origin. If that were not enough, there is nothing in evolution supporting abolition. The racism is patent throughout Darwin's work:
"I could show fight on natural selection having done and doing more for the progress of civilization than you seem inclined to admit. Remember what risk the nations of Europe ran, not so many centuries ago of being overwhelmed by the Turks, and how ridiculous such an idea now is! The more civilized so-called Caucasian races have beaten the Turkish hollow in the struggle for existence. Looking to the world at no very distant date, what an endless number of the lower races will have been eliminated by the higher civilized races throughout the world."
Darwin to Graham, July 3, 1881.
In man the frontal bone consists of a single piece, but in the embryo, and in children, and in almost all the lower mammals, it consists of two pieces separated by a distinct suture. ~~This suture occasionally persists more or less distinctly in man after maturity; and more frequently in ancient than in recent crania, especially, as Canestrini has observed, in those exhumed from the Drift, and belonging to the brachycephalic type. Here again he comes to the same nclusion as in the analogous case of the malar bones. In this, and other instances presently to be given, the cause of ancient races approaching the lower animals in certain characters more frequently than do the modern races, appears to be, that the latter stand at a somewhat greater distance in the long line of descent from their early semi-human progenitors.
Darwin, Descent of Man, Chapter 2.