The realization that Eli Whitney was among the most important Americans at the start of the republic has come only gradually to historians, even historians of technology. Today it is clear that his most famous invention, the cotton gin, saved the United States South economically while encouraging the slave and plantation systems that ultimately led to the Civil War. Yet it is likely that the gin, a simple device that Whitney made in a few days, would have been invented by someone else as well. Whitney's true worth came from the invention of the "American system" of manufacture and the creation of specialized tools. He ... was the first American to utilize standardized parts, an idea probably originally owed to Leblanc, a French arms manufacturer. Whitney's development of cost accounting and establishment of stable government contracts originated methods still used for successful manufacture of all sorts.