One idea, one story: when the salesman started its travel
The Traveling Salesman Problem lies at the heart of Operations Research. Check out the achievements of OR over the years on the figure below ! You already know Dantzig and you will meet Fulkerson when we reach the maximum flow problem.
Each research team reported here in each line managed to solve the corresponding TSP instance exactly (i.e they found an optimal solution and proved its optimality).