They might be "introduced" through a school project, a fan club, a group interested in travel, or one of many other ways. By exchanging letters, they shared mutual interests and taught each other about different cultures, religions, and lifestyles.
With the popularity of online dating sites, many people are starting "pen" relationships with potential partners.
Members might e-mail back and forth many times before deciding to meet.
But this stage is usually brief, with an in-person meeting the definite goal. Can a relationship based on letters turn into the real thing? There are lovely stories from wartime about soldiers falling in love with pen-pal sweethearts.
Having pen pals seems like an archaic idea in our world of instant electronic connections.
There's something nice about taking the time to write a letter, though, and about getting to know someone through their words.
Communicating through letters can turn into a romantic connection, or just be a different kind of friend.
Back before email and free long distance, when a person wanted to communicate with someone who lived far away, they wrote a letter.
Letters took time to write, and time to travel from the writer's door to the recipient's.
Each letter was a little story, a snapshot of the writer's life at that moment.