The "First Letter" refers to the initial written communication sent by one person to another. This can be a personal note, a formal letter, or even an email. The purpose of a first letter often includes introducing oneself, expressing thoughts, or initiating a conversation. It sets the tone for future correspondence and can establish a relationship between the sender and recipient. In historical contexts, the first letter can also signify important events, such as the first written communication between two nations or individuals. Notable examples include letters exchanged by famous figures like Thomas Jefferson and John Adams, which played a role in shaping political discourse.