Mississippi River
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
The Mississippi River forms the western boundary of the State of Illinois.
The Atlantic Ocean forms the state's eastern boundary.
The eastern border of Western Australia is defined by 129 degrees E latitude.
The only state with part of its boundary defined by the arc of a perfect circle is Wyoming. The eastern boundary of Wyoming follows the 42nd parallel north latitude line, which forms part of a perfect circle around the Earth.
7
Hawai'i
South Carolina and the Atlantic Ocean border the eastern side of Georgia. The Savannah River forms the border between Georgia and South Carolina.
The boundary between Illinois and Missouri is primarily a political boundary, defined by the Mississippi River. This river serves as a natural border for much of the state line, particularly in the eastern part. Additionally, the boundary follows specific survey lines established in early statehood, making it a combination of natural and political delineations.
The Mississippi River forms a natural border between Mississippi and Louisiana to the west and flows along the eastern edge of Arkansas. It also serves as a boundary between Mississippi and Tennessee to the north. The river is a significant geographical feature in the region, influencing both the ecology and the economy.
The eastern boundary of Maryland is defined by the Chesapeake Bay and the Atlantic Ocean. It stretches from the northern tip of the state down to the southern border, providing a natural divide between Maryland and the neighboring states of Delaware and Virginia. This coastline features various estuaries, islands, and coastal marshes, contributing to the state's rich maritime ecosystems.