The Territory of Arizona was an organized incorporated territory of the United States that existed from February 24, 1863 until February 14, 1912, when it was admitted to the Union as the 48th state. A forerunner, identical in name but largely differing in location and size, was the Confederate Territory of Arizona that existed officially from 1861 to 1863, when it was re-captured by the Union, after which the Union created in 1863 their Territory of Arizona. Though the Confederate Arizona government of continued to reign in exile until the end of the war in 1865. The two territories played a significant role in the western campaign of the American Civil War.