Briefly explain ONE major difference between Ellis’s and Meacham’s historical interpretations of how Thomas Jefferson came to approve the Louisiana Purchase.

A major difference between Joseph Ellis's and John Meacham's historical interpretations of how Thomas Jefferson approved the Louisiana Purchase is discussed below.

For Joseph Ellis, President Jefferson acted beyond his executive powers to seal the deal for the land purchase of Louisiana from France. He noted that Jefferson reluctantly became an imperial president to make the US an empire today through the ambitious and arduous purchase of the Louisiana land. According to Ellis, this Jeffersonian move defied his 1800 presidential campaign promises to reduce federal power and debts and adhere strictly to the Constitution.

On the other hand, John Meacham, another presidential historian, praised Jefferson for this decisive acquisition. He noted that despite Jefferson's penchant for avoiding controversies, he behaved like the true philosopher and politician by applying his thinking and maneuvering skills to buy the land at a not-too princely bargain of $15 million.

Thus, Ellis's interpretation looked at the constitutionality of Thomas Jefferson's Louisiana Purchase against his campaign promises, while Meacham's interpretation praised Jefferson for acting beyond his character to make decisions in the best interest of the US.

Related link: link

The correct answer to this open question is the following.

One major difference between Ellis’s and Meacham’s historical interpretations of how Thomas Jefferson came to approve the Louisiana Purchase is the following.

For historian Joseph J. Ellis, the issue was the way President Thomas Jefferson proceeded to but the Lousiana territory to the French, knowing that he could have been going beyond his powers as the head of the executive branch. The question for historian Ellis is not that his decision over the territory was right, but the way he implemented that decision that challenged his powers as President. Thomas Jefferson had big hopes that the next step for the American government was in the conquest of the western part of the United States.

For historian John Meacham, the way President Jefferson acted during the Louisiana purchase saga was decisive, trying to protect the Louisiana territory from the Europeans. Meacham thinks that Jefferson never hesitated to exert his power in this particular and special case to defend the sovereignty of the United States. Probably, in other kinds of decisions, Jefferson would have acted differently, more passively, but not in the case of the Louisiana purchase.

the name of the theory is landmass theory.