How many states were there in the United States of America before the Louisiana purchase?
There were 17 states in the United States when the Louisiana Purchase was made in 1803. Ohio had become the 17th state about a month before the purchase.
The biggest effect the Louisiana Purchase had on the United States was the change in the size of the country. The Louisiana Territory more than doubled the size of the country. In addition, the Louisiana Purchase forced Spain and France out of the land now defined as the United States, confining their North American territories to Mexico and Canada, respectively.
The question seems to relate to Napoleon's offer to sell to the United States, the vast amount of land France claimed to own in North America. With that said, Napoleon needed funds to aid his war efforts in Europe. The Louisiana Purchase provided him with funds and increased the size of territory of the United States.