1. I would say Beneficial because when he discovered the "west Indies" he brought back much treasures and gained spain lots of territory.
2. It would have been different because he could've just asked another country or he could have gave up and someone else might have found the new world.
3. This question is up to you...
The reason why grievances was included in the declaration of independence is because the colonies thought it was unconstitutional that the British imposed taxes on them without asking for their consent. Part of this reason are the assertions made in the Stamp Act.
