<a href="https://en.wikipedia.org/wiki/Louisiana_Purchase" id="mwQw" rel="mw:WikiLink" title="Louisiana Purchase">Louisiana Purchase</a>: The United States purchases the <a href="https://en.wikipedia.org/wiki/Louisiana_Territory" id="mwRA" rel="mw:WikiLink" title="Louisiana Territory">Louisiana Territory</a> from France for $15<span id="mwRQ" typeof="mw:Entity"> </span>million, more than doubling the size of the young nation.