Delaware, Kentucky, Maryland, and Missouri were called border states during the Civil War. This is because they were slave states that remained part of the Union.
Delaware, Maryland, Kentucky, and Missouri are the four border states of the North and South. (West Virginia is also a border state)
North Dakota, South Dakota, Wyoming, and Idaho are the four states which border the US state of Montana.
The four states that do not border a waterway are Colorado, Utah, Nevada, and Arizona.
They were called border states
Missouri, Kentucky, West Virginia, Maryland, and Delaware were the five slaveholding border states.
That is called Four Corners, the only place in the US where four boundaries meet in this manner.|
There are four states that border Lake Heron: New York, Pennsylvania, Ohio, and Michigan.
Kentucky, Missouri, Maryland, Delaware.
California and Arizona
Tennessee, Florida, Alabama
The four states that border Texas are Oklahoma to the north, Louisiana and Arkansas to the east, and New Mexico to the west. The nation of Mexico borders Texas to south.