From the Vermont Constitution of 1777:
The House of Representatives of the Freeman of this State, shall consist of persons most noted for wisdom and virtue, to be chosen by the freemen of every town in this State, respectively.
But much was expected of voters, too (emphasis added):
Every man of the full age of twenty-one years, having resided in this State for the space of one whole year, next before the election of representatives, and who is of a quiet and peaceable behavior, and will take the following oath (or affirmation), shall be entitled to all the privileges of a freeman of this State.
“I _________ ___________ solemnly swear, by the ever living God (or affirm in the presence of Almighty God) that whenever I am called to give my vote or suffrage, touching any matter that concerns the State of Vermont, I will do it so, as in my conscience, I shall judge will most conduce to the best good of the same, as established by the constitution, without fear or favor of any man.”
Unselfish voters, wise and virtuous legislators — not just a good idea, but legally required, though of course legal enforcement could be pretty difficult.