The Union Block on Idaho Street was built with local sandstone in 1902. It may have been 40 years after the Civil War, but the Union Block was a symbol from Northern sympathizers chastising Boise's Confederate sympathizers. (There is very little Civil War history in Boise, with much of it coming after the Civil War). The Union Block was designed by John Tourtellotte (from Tourtellotte and Company) and financed by Robert Noble, General John E. Green, Moses Alexander, James Lusk, and C.A. Clark. The contractor of the Union Block was J.W. Smith. The building has two stories and a basement, with a 125-foot long street presence. The building features five arches and large windows, perfect for downtown retail space. After the building's construction, tenants included the Boise Mercantile, the OK Grocery, A.M. Beal's furniture store, Idaho Plumbing and Heating, Christensen's Dance Hall, the Capital News Printing Company, and several attorneys, real estate agents, and an architect and a civil engineer. The Union Block stayed at full occupancy for most of the twentieth century. Unfortunately, during the 1960s it fell in and out of occupancy and was slated for demolition. In the 1990s Ken Howell was awarded the contract for restoration, and by 1995 the building was ready for new tenants. The building now stands as a great downtown landmark. It features several businesses in its first floor, and the second floor ballroom (the Rose Room) is used for many events, including the Fettuccine Forum. The Rose Room was originally intended as a meeting hall. The other side of the second floor is office space. The retail space on the first floor is currently occupied by several restaurants, including Moon's Cafe.

Detail of the Richardsonian Romanesque style Union Block building. Due to Boise's German population, many buildings in Boise reflect this Romanesque style. The style was clustered particularly around 8th Street and Idaho, but there were also other notable buildings with this castle-like style prevalent, including the Natatorium that was located on Warm Springs. Photo by Linda Paul, and used under a Creative Commons licesne.