The main reason why Jamestown was founded is that a group of English people wanted to make their fortunes. They knew, of course, of the riches that had been found by various Spanish explorers in South America and they hoped that they could find ways to become rich in North America as well. This was not the only reason for founding the colony, but it was the main reason.
The charter that the Jamestown settlers got from the king shows that the colonists had at least one other ostensible goal in founding the settlement. The charter speaks of how the colonists are to work at
propagating of Christian Religion to such People, as yet live in Darkness and miserable Ignorance of the true Knowledge and Worship of God…
However, this was clearly not the main goal of this settlement. Instead, the main goal was economic. The settlers were mainly motivated by the desire to get rich. The charter goes on to grant the colonists the right
to dig, mine, and search for all Manner of Mines of Gold, Silver, and Copper … And to HAVE and enjoy the Gold, Silver, and Copper, to be gotten thereof…
This makes clear that the main reason why Jamestown was founded was so that the settlers would be able to find ways to get rich.