Early inhabitants of Mitkof Island used it as a fishing camp in the summer. A Norwegian immigrant named Peter Buschmann settled here in the nineteenth century and built a cannery, sawmill, docks, and other early structures. The settlement was named Petersburg in his honor and it flourished as a fishing port. The port incorporated as a town in 1910 and attracted mostly Scandinavian immigrants, thus giving it the nickname “Little Norway.” Icicle seafoods was founded by Petersburg fishermen in 1965. The Pacific American Fisheries plant was established when the seafood industry seemed to be in a decline. It was purchased by fishermen Gordon Jensen and Magnus Martens teamed up with managers Tom Thompson and Bob Thortenson, Sr. It became one of the largest processors in Alaska for a half century. The board members worked to create, improve, and institute fisheries to sustain Petersburg, as well as many other Alaskan coastal communities. In 1977, it changed its name to Icicle Seaoods. In 2013, Petersburg incorporated itself as a borough. The borough encompassed Petersburg and Kupreanof, in addition to mostly uninhabited areas stretching to the Canada-US border and southern boundary of the City and Borough of Juneau. The City of Petersburg ceased to exist, but the city of Kupreanof remains separate within the borough.