Historic Washington State Park (formerly Old Washington Historic State Park) is a Arkansas state park in Hempstead County, Arkansas in the United States. The museum village contains a collection of pioneer artifacts from the town of Washington, Arkansas, which is a former pioneer settlement along the Southwest Trail. Walking interpretive tours are available throughout the 54 buildings. Washington served as a major trading point along the Southwest Trail, evolving into the Hempstead county seat and later the capital of Arkansas from 1863 to 1865 when Little Rock was threatened during the Civil War. The original plat of Washington was added to the National Register of Historic Places in 1972 as the Washington Historic District. During the 1820s and 1830s, Washington was a stopover for travelers going to Texas. It was originally the county seat of Hempstead County until a new courthouse was completed in Hope, which was designated the seat of government in 1939. The park emphasizes regional 19th century history from 1824 to 1889. It is located in southwestern Arkansas east of Texarkana and near the entrance to Interstate 30. History of Old Washington The Southwest Trail ran from St. Louis, Missouri, to the Red River port of Fulton in Hempstead County some twelve miles from Washington. At the time, the Red River was the border between the United States and Mexico. The trail was a route taken by people headed to Mexican Texas. William B. Travis, Sam Houston, and Davy Crockett each separately traveled through Washington on their way to Texas. On February 14, 1820, Washington was authorized for a post office. That facility remains the oldest continuous postal operation west of the Mississippi River. A new postal building was dedicated on May 29, 1988, by then U.S. Senator David Hampton Pryor. Washington became a town on George Washington's birthday, February 22, 1824. From 1863-1865, Old Washington was the site of the Confederate capitol of Arkansas after the fall of Little Rock to Union forces. The original Arkansas Confederate capital, where the refugee government fled, still exists in the park. It is a part of the Camden Expedition Sites, named in part for the town of Camden, Arkansas, in southern Arkansas. In 1958, the Pioneer Washington Restoration Foundation began preserving the unique buildings and sites that currently lie within the park. The park was established in 1965 and opened eight years later. The Southwest Regional Archives was established