The law changes because people were disagree about it and there's big difference from now
well to be honest if we had advateges why is donald trump president................
Manifest Destiny is the belief that Americans were destined to expand across North America from coast to coast.
The Emancipation Proclamation is an executive order by Abraham Lincoln freeing the slaves.
The Monroe Doctrine was a United States policy of opposing European colonialism into the Americas.
Lastly, The Louisiana Purchase was the purchase of the Louisiana territory by the US from France.
Manifest Destiny is the best answer.
He was the governor of new York