Panamanian independence.

Panamanian people celebrate the 100th anniversary of their independence in Panama City. The United States supported Panama's break from Colombia.

Yuri Cortez/AFP/Getty Images

Americans Take the Panamanian Isthmus

While a fear of "entangling alliances" dominated the early history of the United States, that mindset was disintegrating by the late 19th century [source: Jefferson]. As the U.S. began to acquire territories like the Philippines, Puerto Rico and Hawaii, its leaders became less scrupulous about using gunboat diplomacy to get exactly what they wanted.

In 1902, Congress authorized the purchase of the failed French company's assets, setting the stage for the construction of a canal. However, there was one stipulation to the act. It required that the U.S. first form a treaty with Colombia (which at the time controlled Panama) for the use and control of a canal zone. When negotiations with Colombia failed, the U.S. government supported Panamanian independence -- freeing up the desirable territory from Colombia.

The United States and the fledgling Panama then drafted the Hay-Bunau-Varilla Treaty, with Panama signing over the rights to the Canal Zone without the benefit of a Spanish translation. Many senators were disturbed by the deal and felt that the United States had simply stolen the Canal Zone from Colombia [source: Parker]. But they passed the treaty anyway, believing what was done was done and a canal would be nice. In 1904, the United States paid $40 million for the assets of the Compagnie Universelle and offered Panama alimony of sorts totaling $10 million [source: Parker].

The U.S.-led project got up and running fast. There were some salvageable remnants of the French effort, including buildings, supplies, dredged sea passages and 11 miles of canal. But before work could begin in earnest, two things had to be dealt with: the type of canal that would be built and the fever that made work practically impossible.

The old debate over lock-type vs. sea-level construction ended when President Theodore Roosevelt chose to back Chief Engineer John Frank Stevens' lock-based model in 1906. Stevens' plan called for a dam at the notoriously hard-to-control Chagres River. Damming the river would create GatĂșn Lake and make up a large part of the canal route. Ships traveling toward the Pacific would enter the canal at Limon Bay in the Caribbean, pass through a series of locks that carried them upward in steplike increments, navigate though GatĂșn Lake and descend toward Panama City through another series of locks. The lock plan would carry the waterway over the mountains instead of driving it through them.

By 1906, the Canal Zone was also cleared of yellow fever. The fever, a viral disease, plagued people who hadn't become immune as children. It could appear suddenly and often ended in agonizing death. The at first unbelievable discovery that mosquitoes spread yellow fever and malaria led to a mass sanitary campaign to clean up Panama, Colon and other canal sites. Col. William Gorgas headed sanitation squads that fumigated houses, searched for the stagnant water that could support mosquito larvae and checked screens for signs of rust. The efforts worked; the fever that had been attributed to everything from poor morals to bad dirt was finally eradicated. Work could begin.

Next, we'll learn about canal construction, the locks and find out why the one section of the canal earned the nickname "Hell's Gorge."