Three points in common to three states of the USA

Question

Many years ago I encountered the question: what three states of the USA have three points in common to all three of them? At first this seems impossible since we can put a point in the interior of each state and connect it to the three common points, yielding a planar embedding of $K_{3,3}$. However, this argument assumes that the states are connected. The southwest corner of Kentucky has a tiny region disconnected from the rest of the state, and one can see that Kentucky, Missouri, and Tennessee have three points in common to all three. (See math.stackexchange.com/questions/1653463 for a related question.) Does anyone know the source of this question?