Can someone explain to me how to do this essay?

Hi Trudy. Basically, this type of essay requires you to give an opinion about whether the Louisiana Purchase was really legal under the constitution. It seems even Jefferson wasn't sure. Nowhere in Article II (defining Presidential power) is the President authorized to acquire new territory by purchase or contract, especially land doubling the size of the country. Presumably, such decisions should be made by treaty approved by Congress. So, you might look for articles on what Jefferson wrote about it at the time, and any debates on relevant portions of the constitution, and decide whether Jefferson was right. Basically, since we got such a great price, nobody complained at the time.