In 1850, St. Louis was a major player and a vital hub in western expansion until the breaks turned against them.

Located at the point where the Mississippi, Missouri and Illinois rivers converge, St. Louis was situated at what historians call a "transportation break." This is where goods in transport would naturally change hands or ownership as they moved from one mode of transportation to another. Ports are the most common form of transportation breaks. For example, logs cut in a Washington forest, or wheat harvested in Walla Walla are hauled by truck to Puget Sound ports. From there they are loaded onto a ship destined for ports in Asia or Europe. The transportation break is the point at which the goods were removed from the truck and loaded onto the ship.

When the Rock Island Railroad built a bridge across the Mississippi River in 1856, goods headed west suddenly bypassed St. Louis, which was several hundred miles south. Commerce did not totally dry up in St. Louis but it wasn’t long before the city became a second-string player in the game of Westward expansion.

New York City visionaries created their own transportation break. They built an "artificial river" that linked the Hudson Valley with rich farmland in the Ohio Country beyond the Appalachian Mountains. After completion in 1825, the Erie Canal’s fast-growing stream of trade brought new prosperity to New York and bolstered the trade-as-water analogy.

Merchants in Philadelphia, Boston, Baltimore, and other rival East Coast cities also strived to build their own transportation breaks. They envisioned constructing canals to tap Ohio’s rich agricultural empire. If canals didn’t work, they would employ the new technology of railroads to create new channels of commerce needed for continued growth.

St. Louis visionaries didn’t need to build canals, they had rivers. But the breaks turned against them in 1856. The development of the railroad meant that waterways and cities like St. Louis who depended on them were much less relevant in the saga of the American West.