Which state has a motto containing a 3rd-person jussive subjunctive?

The correct answer is Vermont, which has the motto "Freedom and Unity." The phrase “freedom and unity” can reflect a jussive subjunctive meaning, where freedom is expressed as a state or condition that one hopes for or wishes to achieve, embodying a collective aspiration rather than a direct command.

In the context of Latin grammar, a third-person jussive subjunctive form would be utilized to express a desire or a wish for a subject that is not the speaker (first person) or the listener (second person). This construction is often used in mottos to encapsulate ideals or aspirations, such as those aimed at uniting a populace under the value of freedom.

The other options do not convey this grammatical construct in their state mottos. For instance, Idaho's motto "Esto Perpetua" translates to “Let it be perpetual," but it does not specifically utilize a third-person jussive subjunctive. Similarly, Missouri's motto "The Show Me State" and Illinois's motto "State Sovereignty, National Union" do not exemplify this grammatical construction concerning freedom or unity within a jussive context. Therefore, Vermont stands out as the only state with such a motto.