The Dantzig simplex algorithm was created to solve linear programs for planning and decision making in large-scale enterprises. That is, we want to optimize models of organizational structures specified with a linear objective function and linear inequality constraints. The success of the simplex method led to a vast array of specializations and generalizations that have dominated practical operations research for half a century.
Citation:
John C. Nash, "The (Dantzig) Simplex Method for Linear Programming," Computing in Science and Engineering, vol. 2, no. 1, pp. 29-31, Jan./Feb. 2000, doi:10.1109/5992.814654