According to Arnold, Schwinn and Company, Chicago, IL
According to Wiki on Schwinn history:
The company took advantage of the continued demand for mountain bikes, redesigning its product line with Schwinn-designed chrome-molybdenum alloy steel frames. Supplied by manufacturers in Asia, the new arrangement enabled Schwinn to reduce costs and stay competitive with Asian bicycle companies. In Taiwan, Schwinn was able to conclude a new production agreement with Giant Bicycles, transferring Schwinn's frame design and manufacturing expertise to Giant in the process. With this partnership, Schwinn increased their bicycle sales to 500,000 per year by 1985. Schwinn's annual sales soon neared the million mark, and the company turned a profit in the late 1980s. However, after unsuccessfully attempting to purchase a minority share in Giant Bicycles, Edward Schwinn Jr. negotiated a separate deal with the China Bicycle Co. (CBC) to produce bicycles to be sold under the Schwinn brand. In retaliation, Giant introduced its own line of Giant-branded bikes for sale to retailers carrying Schwinn bikes. Both Giant and CBC used the dies, plans, and technological expertise from Schwinn to greatly expand the market share of bicycles made under their own proprietary brands, first in Europe, and later in the United States
Based on this information your bike was made by either Giant or China Bicycle Company (CBC)