Short answers, pulled from the story.
The U.S. Army adopted the Colt Single Action Army as its standard-issued sidearm in 1873 and kept it in that role until 1892. Colt built the revolver for the government's service revolver trials of 1872.
The Colt Single Action Army earned the nickname Peacemaker and became a fixture of the American Wild West through its popularity with ranchers, lawmen, and outlaws alike. It is also known as the SAA, the Model P, the M1873, and the Frontier.
The Colt Single Action Army has been offered in more than 30 calibers over its history, ranging from .22 rimfire to .476 Eley. The .45 Colt cartridge has always been its most common chambering.
Colt's engravers included Gustave Young, Cuno A. Helfricht, Rudolph J. Kornbrath, and Louis Daniel Nimschke, artisans who had emigrated from Europe. Second Generation guns were later engraved by Alvin Herbert, Earl Bieu, Dennis Kies, Robert Burt, Steve Kamyk, and Leonard Francolini, with Alvin White of A. A. White Engravers among the most sought after.
Yes, George S. Patton carried a custom Colt Single Action Army with ivory grips engraved with his initials and an eagle. He used it during the 1916 Mexican Punitive Expedition and carried it until his death in 1945, and it is now displayed at the General George Patton Museum of Leadership at Fort Knox, Kentucky.
Yes, the Colt Patent Firearms Single Action Army became Arizona's official state firearm after Governor Jan Brewer signed Senate Bill 1610 into law following the 2010-2011 legislative session. Arizona was the second state to name an official firearm, after Utah's earlier choice of the Colt M1911.