 The 1880s were boom times in Duluth; the population was 30,000 in 1887 compared with 13,000 in 1883.Over the next fifteen years, either on his own or in partnership with Wirth (1884–1886) and later Francis W. Fitzpatrick (1889–1896), Traphagen designed buildings for both public and private owners, such as the First National Bank (1888), Turner Hall (1888), Wieland Block (1889), City Hall and Jail (1889), Fire Station No.1 (1889), First Presbyterian Church (1891), and Duluth Central High School (1892).