Hugh Cooper (1865-1935) was born in Sheldon, Minnesota, built his first bridge at age 16, and saw the 40-foot bridge across a creek remain in service for 50 years. After graduating from high school, he became an apprentice at the Chicago, Milwaukee, and St. Paul Railroad and began building bridges in Wisconsin for that firm. In 1891 he turned to hydroelectric power, building water wheels and installing power plants with a Dayton, Ohio, firm, and soon traveled around the world installing power plants. After returning to the United States, he founded the Hugh L. Cooper Company and built a power plant on Horseshoe Rapids above Niagara Falls, completed in 1909. He then helped business leaders in Keokuk, Iowa, and Hamilton, Illinois, who had formed the Keokuk and Hamilton Water Power Company to build a dam across the Mississippi, despite the firm having only $7,500 and five years to finish the work. Cooper secured Toronto insurance financing, but after the 1906 San Francisco earthquake and fire caused financiers to withdraw, he personally sought new backing. In 1909 Stone and Webster agreed to finance the project to build the longest concrete dam ever constructed. The work required its own railroad to move materials and a giant cantilevered traveling crane to place them 125 feet beyond a finished section. Two years into construction, crushing ice in freezing January weather threatened the completed work, but workers using shovels and sandbags held the frozen river back. America's first great dam was completed in May 1913.