Historical maps of Alaskan cities can be found at the website Historic MapWorks. The website offers maps from the early 19th century through the early 20th century.
Maps available on Historic MapWorks include territory maps from atlases and government publications, down to maps of city blocks of major Alaskan cities. Cities covered on the site include Anchorage, with maps available from both 1916 and 1922; Juneau, from 1904 and 1914; and Ketchikan, from 1914 and 1927. The maps of Anchorage show parts of the city block by block. The maps of Ketchikan show both the detail of city blocks and a larger overview of the city.