Complex sentence: He joined the Freie Gemeinde or "Free Thinkers" movement that arose in Germany and after the failed revolution of 1848, he immigrated to the United States in 1850, settling in Milwaukee.
Split into simpler sentences: He joined the Freie Gemeinde or "Free Thinkers" movement that arose in Germany. After the failed revolution of 1848, he immigrated to the United States in 1850, settling in Milwaukee.