Which weapon was nicknamed the "Peacemaker"?

The Colt .45 Single Action Army (SAA; Colt M-1873; or Colt .45 ) revolving cylinder handgun, made famous on the American frontier and the Old West and also known as the "Peacemaker", was invented by Sam Colt in 1832-1835.

In 1835, Colt patented his innovative five-shot revolver. A year later, he founded his Patent Arms Manufacturing Company in Paterson, New Jersey. Among his first customers was John Coffee Hays of the Texas Rangers, who not only purchased Colt’s revolvers for himself but his men. The company at this time however was not doing really great business.

In 1846, with the Mexican War (1846-48) under way, Colt received a major order from U.S. government for 1,000 Colt revolvers. Next, in 1855, Colt opened what was then the world’s largest private armament factory. He employed innovative manufacturing techniques such as interchangeable parts and an organized production line. By 1856, the company could produce 150 weapons per day.

Also, Colt was an effective promoter, and by the start of the U.S. Civil War (1861-65) he had made the Colt revolver perhaps the world’s best known firearm. He died a wealthy man in 1862; his company remained in business. Between 1873 and 1892, the Colt Manufacturing Company went on to produce its standard service revolver (SAA/Peacemaker) for the U.S. military. Overall, the company founded by Samuel Colt has produced more than 30 million pistols, revolvers and rifles. Still in business today, it is making more weapons.