Wooden Ships; Iron Man, Paperback/William G. Mangan

This is the story of a man who left Germany in the 1890's at age 18, signed on as a crew member of a sailing ship then traveled the world finally settling in Seattle, WA. Then as sailing ships gave way to steam, he made that transition. As he moved, he sent postcards to Germany leaving a trail of breadcrumbs marking his location. Each postcard was postmarked thereby revealing the date. Later in years he recounted his adventures to his grandson who obtained the postcards from Germany and tracked his grandfather's travels then combined that with the stories grandfather told him.