The expansion of the railroads in the late 1800s was instrumental in helping the US economy boom. It did this in two ways. First, the railroads created a tremendous amount of demand for goods and labor on their own. As the railroads were being built, they needed huge numbers of people to build them.
Explanation:
That was Louis XIV of France. The original version in French is: <span>l'état, c'est moi. </span>
I would say that the answer is the Panama Canal. Even though construction began in 1904, it is the only canal I can think of which fits the description given.
The canal cuts across the isthmus of Panama and it connects the Atlantic and the Pacific Oceans.