For another example of British hypocrisy don't forget about their shipping many tons of opium into Chinese cities and destroying the social and economic fabric of that nation. The Chinese wrote to Queen Victoria begging her to stop the shipments of opium into China, but these letters were intercepted and she didn't see them.
Opium was making them too much money. Much of the wealth of the Victorian era came from Chinese drug addicts selling everything they could to pay for their addictions.
China was the "sick man of Asia" for a reason, and that reason was British men wrecking them with drugs.
Appeals to morality don't work. Threats to money streams elicit instant reactions as the Opium wars illustrate.
All very good reasons why 19th century Americans didn’t trust Britain or the disunionists who wanted to be dependent on the UK.