"In 1793 Britain went to war against the French following the French Revolution and the cause of the slave-traders appeared to be a patriotic cause: the trade was seen as the "nursery of seamen." Abolition of the trade was postponed although Wilberforce regularly continued to propose legislation for abolition. His moral case was very strong and the evils of the trade were generally admitted. In 1807 the slave trade in the British colonies was abolished and it became illegal to carry slaves in British ships. This was only the beginning: the ultimate aim was the abolition of slavery itself."

from here.