Final answer:
The impact of the British abolition movement during the 19th century was the passing of a law banning slavery in all British colonies in 1833.
Step-by-step explanation:
One impact of the British abolition movement during the 19th century was the passing of a law banning slavery in all British colonies in 1833. Prior to this, Britain had already abolished the slave trade in 1807, but the banning of slavery itself helped to further reduce the institution of slavery in British territories.