In 1793, John Graves Simcoe, the first Lieutenant-Governor of Upper Canada, attempted to abolish slavery. That same year, the new Legislative Assembly became the first entity in the British Empire to restrict slavery, confirming existing ownership but allowing for anyone born to an enslaved woman or girl after that date to be freed at the age of 25. Slavery was all but abolished throughout the other British North American colonies by 1800. The Slave Trade Act outlawed the slave trade in the British Empire in 1807 and the Slavery Abolition Act of 1833 outlawed slave-holding altogether in the colonies (except for India). This made Canada an attractive destination for many African descendant refugees fleeing slavery in the United States, such as minister Boston King.