Born into a large family of cabinet makers, Wilhelm (later anglicized to William) and three of his brothers immigrated to the U.S. and created a company that repaired, restored, and reproduced antique furniture. For over two hundred years his father’s family had worked as furniture makers, and his mother’s family were also cabinetmakers. Franz Potthast and Caroline Gertrud Gutberlet married and raised a family of ten children, six boys and four girls in Borgholz, in North Rhine-Westphalia. William was the oldest son and studied cabinet making with his father, and then went to Berlin for further training, working at a firm that catered to the nobility. The next eldest brother, Vincent, also studied cabinet making and was the first to leave for America. According to family lore, in 1891 he got into a fight at a party and knocked his protagonist out. Vincent panicked, assumed he had killed the man, and got on the first ship he could to the U.S. He landed in Baltimore, where a large number of German-Americans had settled and got work quickly at the Knabe & Company Piano Factory. Knabe was a fellow German and was interested in hiring well-trained German immigrants. Vincent tried to convince his brothers to join him, which William did in 1892. Brother John arrived in 1894, and Theodore was the last to come in 1899. William and Vincent began repairing furniture in the housing they shared. Both married new German immigrants and began having their own large Catholic families.