My great-grandmother (whom I was very close to) immigrated as teenagers from Ireland and settled in the US. She never talked about what led them to leave their homeland. She married a railroad engineer, but he had died before I was born, and all I had of him were objects (railroad tools, clothes, books) of his in her basement, so I imagined him traveling on railroads, his head out the window like in picture books, pulling a string to signal the horn.