February 14: St. Valentine
Although a Christian bishop named Valentine was martyred on February 14 in A.D. 271, there is nothing in this legend to account for the custom of choosing a sweetheart on this day.
By the early 1600s, handmade valentines were customarily sent from admirers to sweethearts. About 1800 the first commercial cards appeared. Cards were usually sent anonymously. As early as 1822, an English official reported having to hire extra postal workers on this day. In 1849, Esther Howland of Worcester, Massachusetts, started selling quality valentines so popular that she was called Mother of the American Valentine.