How did Europeans find out about job opportunities in the US?

For many there was a sort of mythic nature to America, that they all believed they would become rich in the land of opportunity. Stories that got around through normal news outlets about wealthy Americans like the Rathskellers (who were dutch) or the Carnigees (who was Scottish) gave many Europeans hope they could earn that lifestyle. That idea still exists throughout much of the world, but was much more common in the past. And most people took opportunities and like war, famine and the overall suckyness of the 19th and early 20th Century Europe to make their journey to the United States.