Final answer:
The first treaty with Indian tribes referred to is likely the Treaty of Greenville from 1795, which concluded the Northwest Indian War and ceded large areas of the Ohio Valley to the U.S. while promising other lands to the Indian tribes.
Step-by-step explanation:
The first treaty the United States signed with Indian tribes in 1787 to settle regions including Ohio, Michigan, and Pennsylvania was not specified by name in the given text. However, it can be inferred that the treaty being discussed is the Treaty of Greenville, signed in 1795 following the Northwest Indian War. This treaty was one of the early agreements between the United States and various Indian tribes, aimed at settling disputes over western lands. The Treaty of Greenville ceded significant portions of territory in the Ohio Valley to the United States, including areas that would become parts of modern-day Indiana, Detroit, Chicago, and Toledo, while Indian tribes were promised lands beyond the "Greenville Treaty Line."
These treaties, such as the Treaty of Greenville and others, were often made under duress, with the threat of force by the U.S. Army or the loss of crucial resources if tribes did not comply. The treaties were part of a federal policy intended to "civilize" natives by converting them from hunters to farmers, highlighting the complexities and pressures that characterized negotiations between the U.S. government and Indian tribes.