The Mike Mansfield Federal Building and United States Courthouse is a courthouse of the United States District Court for the District of Montana, located in Butte, Montana. Completed in 1904, the building was expanded from 1932 to 1933.It was listed in the National Register of Historic Places in 1979 as U. S. Post Office. It has also been known as Federal Building and U.S. Court House. It is a contributing building in the NRHP-listed Butte Historic District.The building was renamed to honor the late Michael Joseph Mansfield (1903–2001), a U.S. representative and senator, in 2002.Building historyThe building has a colorful history that spans more than 100 years. By the beginning of the twentieth century, the frontier town of Butte was a vibrant copper-mining center, attracting numerous immigrant groups and becoming a "melting pot" of the frontier. Butte became the site of the government's fourth largest immigration office and consequently needed a federal building.The building, which was constructed to serve as a combined courthouse and post office, was designed by Supervising Architect of the United States Treasury Department James Knox Taylor, who was noted for designing many post office buildings between 1897 and 1912. The cornerstone of the building was laid in May 1903. The building was constructed for a cost of $300,000, and was dedicated on December 8, 1904. At that time, it was within a block of several mines and dozens of wood frame lodging and commercial buildings. After the building opened, the elaborate courtroom was the site of numerous naturalization ceremonies as thousands of immigrants became citizens.
