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

Republic of the Congo

Under Title I, Of The State and Of Sovereignty, Article 6, suffrage is direct or indirect and is free, equal and secret. Established by the law all Congolese 18 years of age, enjoying their civil and political rights are electors. (“Congo (Republic of the)'s Constitution of 2015”).

Voting Rights and Suffrage · Country sources (all rights) · Years mentioned: 2015 · Last edited 2022-12-28 · Edit on GitHub