Napoleon could be considered one of the founders of modern Germany. After dissolving the Holy Roman Empire, he reduced the number of German states from 300 to less than 50, paving the way to German Unification. A byproduct of the French occupation was a strong development in German nationalism. Napoleon also significantly aided the United States when he agreed to sell the territory of Louisiana for 15 million dollars during the presidency of Thomas Jefferson. That territory almost doubled the size of the United States, adding the equivalent of 13 states to the Union.