The Old Custom House, now part of the East Tennessee History Center, was Knoxville's first federal building and has been a downtown landmark since 1874. Many East Tennesseans have fond memories of when it was a federal courthouse and post office, and later a headquarters for the Tennessee Valley Authority.

The handsome neoclassical Italianate design was by Alfred B. Mullett (1834-1890), U.S. government chief architect and designer of some 40 other federal buildings. So impressed was Mullett with the local East Tennessee marble that he used it in many later projects, accelerating the growth of what would become a key industry for the region. The Smithsonian's Museum of History and Technology, the National Gallery of Art, and the lobby of New York's Grand Central Station are some of the buildings constructed with East Tennessee marble.

The Custom House includes many interesting architectural features and impressive rooms. The former courtroom on the third floor, for example, includes detailed plasterwork on the ceiling and beautiful chandeliers. Deaderick Hall, the grand hall on the second floor, was once the location of federal offices and is now an art gallery featuring local artists.

In 1973 the Custom House was among the first structures in Knoxville named to the National Register of Historic Places. In 1977 the Custom House was awarded to the public library to be developed into a center for historical research.

The original Custom House has been expanded twice, in 1910 and 2004. Today it is known as the East Tennessee History Center and is home to The East Tennessee Historical Society, the Knox County Archives, and the Calvin M. McClung Historical Collection of the Knox County Public Library, three organizations that work together to preserve the history of East Tennessee.