Little River valleys in 1819 and Stephen H. Long explored the Kiamichi River in 1821. Nuttall and Long were the precursors of empire; the region was actively settled by Choctaw Indians displaced from elsewhere in the United States starting in 1832. After the relocation of the Choctaw Nation to the Indian Territory in 1832, the river defined the political boundary or border between counties and districts. Forming an easily recognizable geographic frontier, it served in this capacity until Oklahoma's statehood in 1907, when the Choctaw Nation ceased to exist and its political subdivisions were eliminated. A Choctaw county was named after the river, although generally using the Choctaws’ spelling, Kiamitia. The river formed the eastern boundary of Jack's Fork County and Kiamitia County, and the western boundary of Cedar County and Towson counties. Navigability of the Kiamichi River was an important goal but proved elusive due to a massive logjam in the Red River which prevented river traffic from going much beyond Nachitoches. In 1825 the Arkansas legislature petitioned the United States Congress to remove the Great Raft, as the logjam was called, so that boats could ply the Red River as far west as the mouth of the Kiamichi and the newly established Fort Towson. Within several years, the Army Corps of Engineers had done so. Security along the Red River, the United States' (US) international frontier with the Spanish Empire was a concern, and the US established a chain of forts along the border. Fort Towson in the Choctaw Nation was one. It was built on Gates Creek near the mouth of the Kiamichi. A military road was built from Fort Smith to Fort Towson through the valley of Little River, switching to the Kiamichi River near its southern terminus. During the American Civil War, the last Confederate Army troops to surrender did so at Fort Towson on June 23, 1865. The Confederate States government had disintegrated by this time, and its individual armies surrendered one by one. While the surrender of Robert E. Lee at Appomattox, Virginia signaled the end to the conflict, it did not truly end until the surrender of the last fighting Southern troops at Fort Towson. Transportation in the Kiamichi River valley was revolutionized between 1882 and 1887 with the construction of the St. Louis and San Francisco Railroad, commonly known as the Frisco. Part of a national network connecting Fort Smith, Arkansas