If the stove and range company of Pittsburghh opened in 1899 why do you have one dated 1897?

I have found this quote in a Genealogy

report that might help:

Later nine different plants, by consolidation, formed the Pittsburg Stove and Range Company, Mitchell & Company being one that went into the new organization. In 1881, Robert A. Duncan and Samuel R. Baldwin bought the Mitchell & Company plant, and in 1882 they erected the New Castle works under the name of Duncan & Baldwin. About 1884 Mr. Baldwin purchased Mr. Duncan's interests and later sold the same to J. C. Graham, and the business was conducted under the firm style of Baldwin & Graham, and in 1899 they consolidated with the Pittsburg Stove and Range Company.