Over time, many factories progressed from smaller concerns (like foundries) to larger operation with larger products (for instance, the machine tool industry).  Sometimes this step was accomplished through a consolidation or merger of similar factories.  For example, Lane-Owens-Dyer (agricultural implements) became Hooven-Owens-Rentschler (machine tools) in 1882.  Hooven-Owens-Rentschler in turn conolidated into a larger corporation, General Machinery in 1928.

H.P. Deuscher Foundry's "Hamilton" Corn Planter, 1891	Hamilton Gasoline Engine  (The Advance Mfg. Co.), circa 1910

Niles Tool Works machinist, 1897	General Machinery employee, circa 1945