1. Arkansas and Mississippi 2. Arkansas and Oklahoma 3. Arkansas and Tennessee 4. Idaho and Montana 5. Idaho and Oregon 6. Illinois and Missouri 7. Iowa and Nebraska 8. Louisiana and Mississippi 9. Missouri and Nebraska 10. Montana and Wyoming 11. Nebraska and South Dakota 12. Oklahoma and Texas 13. Tennessee and Virginia 14. Texas and Mexico (southern border of Texas)In addition, some minor adjustments were made to other States.