If you're looking for copious primary sources to support the broader claims Douglass makes about American churches' support for slavery, they're right here.
Birney wrote this pamphlet (It's about forty pages—that qualified as a pamphlet in the 19th century) to demonstrate to members of various Christian denominations in England that their American counterparts had no intention of getting in the abolition business. Oh, and to beg English churches to use their influence on American churches to bring them around to the idea that slavery might be, you know, bad.
Most of the pamphlet consists of quotes taken from various ministers and church governing bodies in both the North and South. According to these quotes, most churches in the 1830s and 1840s embraced a few main ideas:
Birney wants his English readers to know, though, that it's not all American churches who feel this way—just most of them.
Garrison's anti-slavery newspaper, The Liberator, was the voice of a generation of abolitionists. While he and the abolition movement had their differences at times, Garrison was a superb writer who never pulled his punches.
Love him or hate him, you couldn't ignore him.
The Liberator was some of the first anti-slavery literature Douglass read when he came North, and its influence on him is hard to overestimate. "The Church and Prejudice" was given early in his career as an activist, when he and Garrison were tight.
With the phrase, "Our country is the world—our countrymen are mankind," as its slogan, The Liberator agitated for emancipation for thirty-four years.
Charles Colcock Jones was a Presbyterian minister and plantation owner. He was born into a plantation family in Liberty County, Georgia.
He struggled with the morality (or immorality) of slavery, especially after spending time in the North away from his plantations. However, he reconciled himself to slavery by concluding that his only responsibility was the spiritual welfare of slaves—not their physical, civic, or temporal welfare.
Sure, Chuck, whatever helps you sleep at night.
This book is part history, part evangelical tract, and part how-to guide designed to influence white clergymen and slaveholders to provide Christian religious instruction to slaves. After Nat Turner's Revolt in 1831, education of slaves had fallen off, and Jones attempts to impress upon slave owners the idea that they're responsible for their slaves' spiritual lives, and thus their religious education.
George Fitzhugh was born into a Virginia slaveholding family in financial decline. He was an ardent defender of slavery, believing Africans were racially inferior and that it "elevated" Africans to be around whites.
Sociology for the South, or The Failure of a Free Society argues that the free trade, free labor, capitalist system is worse for laborers than the paternalistic system of slavery, in which (in theory) slaves are treated well. As part of his larger argument in favor of pre-Marxist socialism, Fitzhugh attempts to discuss the role of religion in a slave society and to provide Biblical justification for slavery.
While there's no question that Fitzhugh's views were racist, he's gotten fresh attention from scholars interested in comparing his critique of capitalism with Marxism and related theories.
First, can we just say that "Thornton Stringfellow" sounds like he should be in a Dickens novel?
Okay, moving on.
First, Thornton Stringfellow was one of many people spilling ink trying to prove that the Bible was a pro-slavery document. He was pretty irked at abolitionists taking the moral high ground, so he was determined to pull them off it by using the Bible to defend slavery. In this piece, he makes four main points:
Abolitionists just don't know how to read the Bible, says Stringfellow. If they did, all this would be clear and he wouldn't have to waste his time schooling them.
MLK, Jr., no slouch at speechmaking himself, was asked to talk about racism at Western Michigan University in December 1963, four months after rocking the nation with his "I Have a Dream" speech in Washington, DC.
It was a wide-ranging speech that touched on all aspects of the Civil Rights Movement, including the failure of the churches and their congregants to end segregation:
We must face the fact that in America the church is still the most segregated major institution in America. At 11:00 on Sunday morning when we stand and sing and Christ has no east or west, we stand at the most segregated hour in this nation. This is tragic.
122 years after Douglass' speech, Dr. King didn't hesitate to also call out the church and its leaders for the persistent problem of racism. Of course, slavery was long gone, but segregation was alive and well. King, a minister, wanted to use the churches as an institution to fight for equality, whereas Douglass saw the churches as complicit in slavery in his day and felt alienated from them despite his Christian faith.
For a look at the similarities and differences between Douglass and MLK, Jr., check out Boston University's handy guide.