Here's the block. The convention center & Pheonix Hotel stands there today.
Here's a detail on the Capital Brewery.
These images are from the 1895 Sanborn Map of Salem.
Here are more images of historic Salem Breweries. And images of beer and hops. I'll intersperse tap listings with notes on some of them.
Notes on 19th century Saloons are here. And notes on 19th century hops trade & breweries. About the Capital Brewery it said:
Sam Adolph founded the first Salem brewery with John Brown at Church and Trade Streets in Salem in 1862. When Adolph's brewery burned in 1869, it was relocated to the southwest corner of Cottage and Trade streets. In 1885 Adolph joined with two of his employees, Maurice Klinger and Seraphin Beck, to build the Capital Brewery on the northeast corner of Commercial and Trade Streets, which produced mainly draught beer but also had a small bottling plant behind the brewery.Over at Brewerygems there's a terrific history of the Salem Brewery Association, including the Capital Brewery. Jeff Alworth at Beervana has an excellent collection of notes on various aspects of regional brewing history.