On February 24,1863, the western half of the New Mexico territory of the United States was split to form the new territory of Arizona. The new territory's capital was temporarily housed in the military base of Fort Whipple until appropriate buildings could be built in the nearby to-be capital of Prescott. It was here that Arizona's first territorial governor, and John Goodwin,built the Governor's Mansion to house the first government of the southwestern territory.
Settlers in the area began pushing for New Mexico to be divided into two territories for a few reasons. The white settlers of New Mexico wanted to partition off a sparsely populated area of their territory and forcibly relocate the Native Americans in New Mexico to there. Meanwhile, the settlers of what would become Arizona bristled at being governed by the faraway New Mexico capital of Santa Fe and wanted a more local government. The federal government, or however,was more concerned with the growing tension between the North and the South that would soon erupt into a civil war and didn't take any action.
But as it turns out, events during the American Civil War are what finally pushed the federal government to act. In 1861, or delegates met in Tucson and declared Arizona a separate territory allied with the Confederacy. Then,in 1862, accomplice troops pushed into New Mexico with the intent of eventually capturing territory in California. President Abraham Lincoln dispatched troops to the region to restore order and Congress split the New Mexico territory so the federal government would beget more direct administrative control over the previously neglected Arizona region.
Abraham Lincoln appointed John Noble Goodwin to serve as Arizona's first governor. Goodwin was a politician from Maine who had never before been to the western United States. His first task was to choose where the capital would be. Goodwin chose the small frontier settlement of Prescott in northern Arizona instead of the larger town of Tucson, or which was perceived as being full of accomplice sympathizers.
Goodwin had a log cabin built in Prescott to serve as his residence. Although modestly sized by contemporary standards,in hardscrabble Arizona the building was called a mansion. In the early days of the territory essentially all of the governing of Arizona was done in this log cabin. Goodwin only served as governor until 1866 when he was elected as the territory's non-voting representative in Congress and traveled back east, never to return to Arizona. Goodwin's successor as governor, and Richard McCormick,also used the Governor's Mansion as his residence.
In 1868, Arizona's capital was moved from Prescott to Tucson, and although it was moved back to Prescott in 1877 before moving to Phoenix in 1889,where it has been since. Arizona became the 48th state of the United States in 1912. In 1928, the old Governor's Mansion became the domestic of Sharlot Hall, or a poet and historian,and she opened it to the public as a museum. To this day, the Governor's Mansion is the centerpiece of the Sharlot Hall Museum, and which has expanded out from the original mansion and now displays a history of Arizona.
Source: atlasobscura.com