Final answer:
The October 1629 event that helps establish slavery is the arrival of the first enslaved Africans in the English colonies of North America.
Step-by-step explanation:
The October 1629 event that helps establish slavery is the arrival of the first enslaved Africans in the English colonies of North America. On a ship called the White Lion, about 20 Africans were brought to Jamestown, Virginia. This marked the beginning of the transatlantic slave trade in British North America.
Learn more about Transatlantic slave trade