What about British anti-slavery/American travel texts? Too obvious? If not, one personal favorite that’s easily overlooked is Frances Anne Kemble’s
Journal of a Residence on a Georgian Plantation,
which was written in the 1830s and published in England in 1863. I’ve had great luck teaching the opening few letters, followed by excerpts. (James loved her Shakespeare performances, by the way–and presumably knew her history of having traveled to the US, married, and only then discovered that her new American husband was a slaveholder.)