There were not many literate miners living in Idaho City in the 19th century, but every town needs a newspaper for its residents to keep up with world events and the Civil War that raged thousands of miles away.
"Idaho World" newspaper was founded in 1863 by the Butler Brothers. They found printers and a blacksmith in the mining camp to get the paper started and subscriptions cost $12 or 3/4 ounce of gold. The newspaper published pro-Union and Confederate papers, which was a big topic of discussion during this time.
The Idaho World building was built in the same style as the Merc to prevent fires. It was used for other businesses for short periods of time, but most of its time it was the newspaper office. Today, Idaho World houses an exhibit of historical printing equipment.
Mom was bummed that the Idaho World building was closed on Memorial Day because she would have loved to have gone inside to see the printing equipment. Her father worked for the "Providence Journal Bulletin" in Rhode Island in the middle of the 20th Century, and she was a proofreader for an insurance company's printing facility many years ago. It would have been a sentimental visit for her, but it will have to be done another time.