What is the oldest written source in this country that mentions this right?

Saint Vincent and the Grenadines

Under article 27 all citizens who are over the age of 18 and meet proper residence requirements are entitled to vote for representatives based on the principles of universal suffrage by secret ballot. (Constitute Project, “Saint Vincent and the Grenadines’s Constitution of 1979”).

Voting Rights and Suffrage · Country sources (all rights) · Years mentioned: 1979 · Last edited 2022-12-28 · Edit on GitHub