The Thor was made by the Aurora Machine & Tool Company in Chicago, Illinois. They made the first engines for Indian in 1902 and then started their own line in 1903. The 1200cc motor in this bike was only made until 1915 but Thor assembled bikes up to 1918. Several thousand were built. Aurora also made home appliances and at one time sold a combination clothes washer/dishwasher, which probably speeded up their eventual demise.