Napoleon was in great need to money to fund their army that us why they sold Louisiana to the America.
Explanation:
Economical: Financially, the Napoleon was in great need of money to support their army so that they can protect them in the war situations.
Political: Once Napoleon had command of Spain, the Louisiana Territory was shifted to France but France had already suffered major defeats in an attempt to protect its colonies (American) in the Caribbean more specifically, the Haitian Revolution of 1791 - 1804.
An entire French army was destroyed in the war. By selling Louisiana to the US in 1803, Napoleon decreased the need to safeguard it against the British, and he hoped to bring America back into an alliance with France to protect the territory (against the British) Can.
