What important precedent did Thomas Jefferson set by purchasing the Louisiana Territory?

Thomas Jefferson set an important precedent by purchasing the Louisiana Territory in 1803, as it expanded the power of the federal government in acquiring land and significantly increased the size of the United States. This decision, made without explicit constitutional authority, demonstrated a broader interpretation of presidential power and the Constitution. It also paved the way for future territorial expansion and the concept of Manifest Destiny, influencing American politics and westward expansion for decades to come.