Klaus was born in the town of
Bruttig, in the
Rhine Province in western
Prussia (now western Germany). He was the fourth of five children. He first came to Green Bay in 1849. By 1853, he was successfully managing a small hotel called the Green Bay House. In 1854, Green Bay was incorporated as a city, and in the spring of 1855, Klaus was elected the first city treasurer. He served one year as treasurer and then returned to his hotel business. After the
Panic of 1857, Klaus entered the lumber industry, first building a sawmill, then acquiring others. With these resources he entered the
shingle trade. Over the next decade, Green Bay grew to become the primary shingle market in the world, and Klaus became the largest buyer, manufacturer, and trader of the material in the United States. Klaus became a major investor in Green Bay, buying and building all around the city. On the 1870 census, Klaus listed his real-estate value as $120,000 ($ in dollars). ==Political career==