Spain is the only country to border Portugal to the east.
The country is Eritrea, and it's eastern boundary is formed by the Red Sea.
The southern half of the eastern boundary of Alabama is the Chattahoochee River.
The Atlanic Ocean
Minnesota.
the country that forms the northern boundary of the United States is Canada :)
The Connecticut River
Mississippi
Mississippi
The Mississippi River is the East boundary for Arkansas.
Two rivers partially form Illinois State's Eastern boundary. The Wabash River is one river that forms Illinois' boundary. The Ohio River is the other river that forms the state's boundary.
Mississippi River