Question

insert dashes where needed.
captain john smith one of the first leaders of virginias jamestown colony created a dictionary containing more than five hundred powhatan words, including chesapeake, opossum, persimmon, and raccoon.

Explanation:

Dashes are used to set off a non-restrictive appositive phrase that adds extra, non-essential information about the noun it modifies. Here, "one of the first leaders of Virginia's Jamestown Colony" is extra information about Captain John Smith, so it should be enclosed in em dashes.

Answer:

Captain John Smith — one of the first leaders of Virginia's Jamestown Colony — created a dictionary containing more than five hundred Powhatan words, including Chesapeake, opossum, persimmon, and raccoon.