What were obstacles to the Louisiana Purchase?

Answer 1

The Louisiana Purchase resulted from the desire of Thomas Jefferson and his administration to secure permanent access by frontier traders to the Mississippi River, and the most effective method seemed to be buying the Port of New Orleans. France had ceded its claims to the Mississippi Valley (Louisiana) to Spain as a result of the French and Indian War/Seven Years War, but Napoleon had secretly regained sovereignty in 1801, and decided against trying to establish New France against competition by Britain and the new United States; instead he sold all of Louisiana to the US.

However:

- France did not have full legal rights to Louisiana, both Spain and Britain having competing claims. But clauses omitted from the Third Treaty of San Ildefonso provided Napoleon enough leeway. He bypassed the French assembly, while Spain acquiesced to the US purchase, possibly because they thought it would only be for New Orleans.

- Additionally, Federalists argued that the US buying territory was unconstitutional. However, the Presidential power to negotiate treaties proved authority enough, as the House failed to block the treaty. Some Federalists likely worried about war with Spain in the West, as well as the prospect of new slave states being created from the territory.