The 125-foot-wide building in the center of these structures is actually the Union Block all by itself, as it says on the sandstone façade. It was designed in 1899 by architect John E. Tourellotte and completed in 1902. This was during a little building boom in Boise. As plans were announced for the Union Block adjacent property owners jumped on the bandwagon, matching facades on their buildings to that of the Union Block. The Idaho Statesman of July 27, 1901, noted that “The adjoining owners agreeing to immediately build, and in conformity with the plans of the new structure, means practically an entire stone block for Idaho Street.”
According to the Idaho Architecture Project Website, the Union Block Building is a Richardsonian Romanesque-styled building. The sandstone came from Table Rock and the whole thing cost $35,000 to build.
Why was the building called the Union Block? The original owners were Union supporters who wanted to show that and thumb their collective noses to southern sympathizers who were still prevalent decades after the Civil War.
This was apparently a common tactic. Boise’s Union Block was placed on the National Register of Historic Places in 1979. Joining it in that honor are at least eleven other Union Blocks around the country, including one in Iowa, two in Kansas, one in Maine, two in Michigan, one in North Dakota, one in New York, one in Ohio, one in Oregon, and one in Utah.