The 13th Arizona Territorial Legislative Assembly was a session of the Arizona Territorial Legislature which began on January 12, 1885, in Prescott, Arizona. The session's accomplishments included allocation of a variety of territorial institution including a university, normal school, prison, and insane asylum. Nicknames bestowed to the session include the "bloody thirteenth" due to fights in the halls of government and nearby saloons, and the "thieving thirteenth" due to the very large appropriations approved by this legislature.
During the Apache Wars, the primary source of cash for many Arizona towns was a nearby military post. By the mid-1880s, subjugation of the Apache was largely completed and the settlements saw territorial institutions as an economic replacement for the forts. The territorial capital and an anticipated insane asylum were considered the best source of revenues. A potential university and normal school were considered of lesser importance with a common line of the day being, "Who ever heard of a professor buying a drink?"
The other big concern facing the territory was an influx of Mormon settlers. About 2000 Mormon settlers had arrived in Arizona Territory during 1884, raising their totals to 5000 settlers, and their political opponents suspected the LDS Church was trying to create a large enough voting block to take over Arizona (at the time a majority of Idaho's legislature was Mormon and the church had been able to determine Wyoming's delegate to Congress). In response to the influx, five of the settlers were tried and convicted of polygamy. Political response to the convictions was largely favorable, with the New York Times writing, "This is a very good beginning. If there are among the new settlers other men who have violated the law they should be promptly prosecuted and sent to the penitentiary. In no other way can the growth of polygamy in Arizona be checked."
Prior to the legislative session, a group of Tucson businessmen had raised a US$5,000 slush fund to lobby for the return of the territorial capital. The delegation from Pima County was delayed by flooding on the Salt River, forcing a detour through Los Angeles and Sacramento, California, before they could reach Prescott. While this detour was occurring, 7 of the 12 members of the Council met privately and had reached an agreement to block any legislation that would move the capital from Prescott, the penitentiary from Yuma, weaken anti-Mormon legislation, divide Cochise county, or create anti-railroad legislation.