The United States Post Office and Courthouse is currently the only federal office building to straddle a state line. The present Texas-Arkansas state boundary, established in 1841 by the United States and Republic of Texas, passes through its center. Each state had separate post offices until 1892, when the first joint office was built on this site. That building was razed in 1930, and the present structure was completed in 1933. Its base is of Texas pink granite, while its walls are of limestone from Arkansas.