At the beginning of the revolutionary war to break away from Britain and then the colonists wrote the Declaration of Independence. That told Britain that they were a separate country from England.
The Declaration of Independence was signed and complete on 1776 and it put hope into the Americans and it also told them to prepare because England will be mad.
In 1803 the colonists wanted New Orleans because they can use the Mississippi River for shipping but France owned it so they had to buy it from them. Their original offer was 10 million dollars for New Orleans but France threw in the Louisiana Territory because they needed money for the war they were having.
In 1805 we did not know what was in the Louisiana Territory so we sent Lewis and Clark to explore the Louisiana Territory and make maps of their surroundings.
After the Lewis and Clark expedition people started moving in and then we discovered British were there and they were attacking us by land and by sea which led to the War of 1812 which ended with the Treaty of Ghent.
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