The 1865 Dubuque City Directory listed the corner of 2nd and Main.
The ownership of the business changed in 1866 from a Mrs. Mulqueney to her nephew. The saloon was turned into a retail grocery store. (1)
The 1874-1875 through 1880 Dubuque City Directory stated that this business was located at 144 2nd.
"Changes Extraordinary," Dubuque Herald, August 8, 1866, p. 4. Online: https://news.google.com/newspapers?nid=uh8FjILnQOkC&dat=18660808&printsec=frontpage&hl=en