The United States of America wanted more land since it is now a new country. They enforced that the Native Americans should get out which they didn't take likely. The United States believe they had a right to take the land and advanced into the western territory
War and Bloodshed
The first reason why the Battle of Fallen Timbers occurred was that the Americans began settling in the land that was claimed by the Native American's. They had a right the land first since they've been there for the past 1000 years.
The loss of the Native Americans
Another reason why the battle occurred was that not only does the west have land but it has natural resources, soils, and minerals. The conflict then started and had breakouts because both sides wanted access to the western land.
Impact: A forced treaty
Fights and breakouts occurred frequently between each side and Washington had to send troops in to put an end to the rebellions occurring. This was the war known as the Battle of the Fallen Timbers between the Native Americans and the United States.
The Native American's eventually lost since the Americans had advanced weapons therefor leading a conclusion to the end of the war. This results in the American side winning and claiming the western land.
The effect of the battle leads to the Native American's being forced into a treaty. This is known as the treaty of Greenville. This was basically a national policy to put down any Native American resistance.