The word "suffrage" comes from the Latin suffragium meaning "to support." It already had the connotation of voting in classical Latin, and may have been used as well for a special tablet on which one recorded a vote.
It likely came into English through French. In Middle English, the word took on ecclesiastical meanings, as well, of intecessorty prayers. In the 15th and 15th centuries in English, it was also used to mean "support."
By the 16th and 17th centuries, "suffrage" was in common use in English to mean a vote in favor of a proposal (as in a representative body like Parliament) or of a person in an election. The meaning then broadened to apply to a vote for or against candidates and proposals.
In Blackstone's commentary on English laws (1765), he includes a reference, "In all democracies .. it is of the utmost importance to regulate by whom, and in what manner, the suffrages are to be given." The Enlightenment, with emphasis on equality of all persons and "consent of the governed," paved the way for the idea that the suffrage, or ability to vote, should be extended beyond a small elite group became a popular demand. "No taxation without representation" implied that one would be able to vote for those representatives. Universal male suffrage was a call in the first half of the 19th century, and then some (see Seneca Falls Woman's Rights Convention) began to extend that demand to women as well.
