A patent was filed on August 20,1896 by employees of Almon Strowger, A. E. Keith and the brothers John and Charles Erickson; patent No.597,062 was granted on January 11,1898.
A patent was filed on August 20,1896 by employees of Almon Strowger. A patent was filed on August 20,1896 by employees of A. E. Keith. A patent was filed on August 20,1896 by employees of the brothers John and Charles Erickson. Patent No.597,062 was granted on January 11,1898.