The Texas State Capitol is the capitol building and seat of government of the American state of Texas. Located in downtown Austin, Texas, the structure houses the offices and chambers of the Texas Legislature and of the Governor of Texas. Designed in 1881 by architect Elijah E. Myers, it was constructed from 1882 to 1888 under the direction of civil engineer Reuben Lindsay Walker. A $75 million underground extension was completed in 1993. The building was added to the National Register of Historic Places in 1970 and recognized as a National Historic Landmark in 1986.