One of the first patent pools, Sewing Machine Combination, was formed in 1856, by sewing machine manufacturers Grover, Baker, Singer, and Wheeler & Wilson, all accusing the others of patent infringement.
In 1917, the two major patent holders for airplanes, the Wright Company and the Curtiss Company, had effectively blocked the building of new airplanes, which were desperately needed as the United States was entering World War I.