Carl and Josephine kept a household book where they noted down food and rent expenses very carefully. The first entry of April 1927 was written by Josephine, and the last was entered by Carl seven months after her death in June 1937. As well as giving us a glimpse into the eating habits of German emigrants it is also interesting for its mixture of English and German. On December 23, 1927 their Christmas shopping is listed as "1 Puter (Göger) (5 ¾ lbs.), 1 beutel potatoes, 1 dz. oranges & vegetables, Groceries & bread". For the New Year they bought "Wurst & Sauerkraut, Limburger & Bohnen, Fleisch, Bread, starch & sugar".

In 1929, the year of the Wall Street Crash, Carl became an American citizen. The economic crisis also hit Rochester – and this clearly prompted Carl to use the strong dollar for a trip to Germany. In 1930, seven years after his emigration, he and Josephine crossed the Atlantic in the opposite direction. The zither left behind among Carl's possessions probably dates from that first trip to Germany in 1930. The young couple travelled to the mountains of Bavaria and Austria. On the trip Carl visited Munich and purchased a case of mathematical instruments from the renowned German firm of Riefler. Carl worked on the design of precision-mechanical systems, and accurate tools were of great importance to him. According to the receipt, the case cost 73.95 Reichsmark, or 17.61 Dollars at the official rate.

While in Munich, German-Americans Carl & Josephine also visited the famous "Platzl" cabaret, where stars like Bally Prel, Weiss Ferdl and Eringer Seppl performed. The guests were provided with a small song pamphlet with the texts of German folk songs, probably for the purposes of singing along, and Carl kept it all his life. A few coins also survive from that holiday trip.