On 28 November 1821, the Mississippi state legislature authorized this location on the Pearl River as the new location for the new state capital. The survey report indicated that the area had "beautiful and healthful surroundings, good water, abundant timber, navigable waters, and nearness to the Natchez Trace," which was an important trading route. (Jackson Convention and Visitors Bureau).
While the commercial vibrancy of the downtown area, as with many American downtowns, was decimated in the mid 20th century by suburban sprawl, a significant amount of government activity and attractive architecture still survived when I visited in the 2010s. I frequently had transfer layovers at Jackson Union Station between the Amtrak City of New Orleans train and Greyhound bus service to Louisiana, and I occasionally used the time to explore a bit.
Many of the notes about these building come from a self-guided walking tour guide from the Mississippi Department of Archives and History.