Pennsylvania and Delaware
Maryland's northern boundary is defined by the Mason-Dixon Line, which serves as the border between Maryland and Pennsylvania.
Kentucky
In most cases the eastern boundary of something will touch the western boundary of the next door something. Where "something" can be a state, province, country, estate, ocean, lake river, Earth plate etc.
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.
Maryland and Northern California.
the country that forms the northern boundary of the United States is Canada :)
The Fairfax Stone serves as a boundary marker between three U.S. states: West Virginia, Virginia, and Maryland. It is located in the Monongahela National Forest and is historically significant as it marks the original survey point for the boundary between Virginia and Maryland. The stone also symbolizes the division between the Northern and Southern states during the Civil War era.
The Potomac River forms most of Maryland's western boundary.
Norway, Finland, and Russia were creating a northern boundary.
West Virginia is in the Northern Hemisphere.
Canada.
You can locate the US state of Maryland in both the Western and Northern hemispheres.