Karen Sands-O’Connor. Children’s Publishing and Black Britain, 1965-2015. New York: Springer, 2017, p. 11:

As I have suggested elsewhere (Sands-O’Connor, 2008:38-39), Edward Lear, in 1846, included a Jamaican in his Book of Nonsnse (Jamaica being handily rhymed with Quaker); his poem looks at the abolitionists (many of whom were Quakers) and suggest comically that perhaps they were not quite ready for the real-life consequances of their intellectual commitmaent to freedom and equality.

Karen Sands-O’Connor. Soon Come Home to This Island: West Indians in British Children’s Literature. New York-London: Routledge, 2013, pp. 38-39:

… but the Quakers and their role in the abolitionist movement were not forgotten. More than a decade after the abolition of slavery, Edward Lear, produced his Book of Nonsnse (1846). In this book of near-limericks [?],  he mentions both Quakers and the West Indies in a way that suggests the prevailing sentiment concerning radical religion:

There was an Old man of Jamaica,
Who suddenly married a Quaker:
But she cried out, “Oh, lack! I have married a black!”
Which distressed that Old Man of Jamaica.

One of the frequent arguments against the freeing of slaves (and their eventual inevitable equality within society) was the notion that it would lead to mixed-race marriages. Gretchen Holbrook Gerzina, who notes the common practice of servants’ marrying across racial lines in England, at the same time points out the fear among the middle and upper classes that blurred racial lines might extend upward. “The worry about white employment,” she writes, “covered a thinly disguised fear of miscegenation” (Gerzina 1995, 180). Lear’s limerick suggests that the Quakers, as well-meaning as they might have been, were not prepared to deal with the consequences of all their abolitionary efforts. Lear’s nonsense, John Rieder writes, “is a playground. It separates itself from the ‘real’ world, letting loose a number of possibilities, including dangerous and violent ones, and at the same time disconnecting those possibilities from the real world” (49). But Lear’s suggestive word choice — his Old Jamaican did not, for instance, marry a baker — argues otherwise. The master of the nonsense world was in fact very aware of the danger and violence of the real world’s playground, and the distress that the well-meaning European brought to it.