As socialist meetings and press had been banned in Germany, Steinmetz fled to Zürich in 1888 to escape possible arrest. Faced with an expiring visa, he emigrated to the United States in 1889. He changed his first name to Charles in order to sound more American and chose the middle name Proteus after a childhood taunt given to him by classmates. Proteus was a wise hunchbacked character from the Odyssey who knew many secrets and he felt it suited him.
Cornell University Professor Ronald R. Kline, the author of Steinmetz: Engineer and Socialist, contends that other factors were more directly involved in Steinmetz's decision to leave his homeland, such as the fact that he was in arrears with his tuition at the University of Breslau and that life at home with his father, stepmother, and their daughters was full of tension.