Tennessee or Missouri; both share borders with eight states.
Both Tennessee and Missouri share borders with eight other states.
Missouri has to be one of them and Tennessee is the other.
Missouri and Tennessee each share borders with eight states.
Tennessee and Misouri both share borders with eight states.
Russia
No state borders 9 other states, the most borders any state has is 8 (Tennessee and Missouri)
Missouri and Tennessee both border the most states, 8.
Missouri and Tennessee are the only U. S. states adjacent to eight other states each.
South Australia :)
Tennessee borders eight other states: Kentucky, Virginia, North Carolina, Georgia, Alabama, Mississippi, Arkansas, and Missouri.
Missouri and Tennessee both border the most, with 8 states.