No More Auction Block - From The Jubilee Singers by Gustavus D. Pike, 1873
and quoted in The Music of Black Americans, A History by E. Southern, 1983

No more auction block for me
No more, no more
No more auction block for me
Many thousand gone

Songs of the Underground Railroad;
See Wikipedia page

Harriet Tubman - words & music by Walter Robinson

One night I dreamed I was in slavery, 'bout 1850 was the time
Sorrow was the only sign, nothing around to ease my mind
Out of the night there came a lady leading a distant pilgrim band
"First mate!" she yelled, pointing her hand
"Make room on board for this young man"

Amazing Grace - published in 1779, with words written by the English poet and Anglican clergyman John Newton (1725–1807).

Newton wrote the words from personal experience. He grew up without any particular religious conviction, but his life's path was formed by a variety of twists and coincidences that were often put into motion by his recalcitrant insubordination.

He was pressed (conscripted) into service in the Royal Navy, and after leaving the service, he became involved in the Atlantic slave trade.

In 1748, a violent storm battered his vessel off the coast of County Donegal, Ireland, so severely that he called out to God for mercy, a moment that marked his spiritual conversion.

He continued his slave trading career until 1754 or 1755, when he ended his seafaring altogether and began studying Christian theology.

(From Wikipedia)

Not necessarily from British tradition, but often well-known in Britain.