The British did not initiate, but they came to dominate the Atlantic slave trade. Few expressed moral or ethical doubts about slavery. The Anglican church, was directly involved in slavery. When a Christian voice was raised against the slave trade, it was led by Quakers who also played a critical role in the campaign to end the slave trade.
"Slavery, the Slave Trade and the Churches,"
Quaker Studies: Vol. 12
, Article 3.
Available at: http://digitalcommons.georgefox.edu/quakerstudies/vol12/iss2/3