Half a Century of PRL

Fifty years ago, Sam Goudsmit started an experiment: Physical Review Letters. Since 1958, the experiment has thrived. PRL has gone through many changes, published many important papers, and become a leader in international scientific publication.~ I will trace the rise of PRL from its early 20th century roots as ``Letters to the Editor,'' through changes in editorial process and advents of new technology. Along the way I'll show what has gone on behind the scenes, and give a glimpse of our plans for the future.