Fifth structure to serve as seat of justice for Lavaca, created originally as "La Baca", a judicial county, by Congress of Republic of Texas in 1842. Declared unconstitutional along with other judicial counties, it was created anew by first Legislature of State of Texas on April 6, 1846, and organized on July 13, 1846. Earliest courthouse was of logs, and for an interval after that one burned, court was held under a liveoak tree in old town of Petersburg.
This is third courthouse on this site since county seat was moved to Hallettsville, 1852. Richardsonian in style, it is of Mineral Wells brown sandstone and has base and trim of Mills County grey stone. Eugene T. Heiner of Houston, noted for his public buildings, was the architect. Contractors A. T. Lucas and C. H. and J. Stadtler erected the structure in 1897-1899.
Led by members of Hallettsville Schuetzen Verein, Silver Cornet Band, fire department, Sons of Hermann, and other orders, county dedicated the building July 4, 1899, with Judge P. H. Green giving the main address. Courthouse square was selected by Texas Society of Architects in 1970 for a restoration study. The courthouse was placed on the National Register of Historic Places in 1971.