Answer both they are short. 27 points

Why 1807 significant
The members of the Society for the Abolition of the Slave Trade decided to concentrate on a campaign to persuade Parliament to prohibit the trading in slaves, for tactical reasons. They felt they were more likely to succeed, than if they demanded the abolition of slavery itself throughout the empire.

Why 1833 significant
The British Parliament passes the Slavery Abolition Act 1833, ultimately giving slaves in much of the British Empire their freedom (enacted 1834).

Credicts to the owner