Not being an American I can only offer an opinion based on what little I've read or heard about the United States presidents of the 20th Century. My guess would be Franklyn Delano Roosevelt (did I spell that correctly) After all, he managed to pull America out of the greatest economic depression known to humanity, the 1929 stock market crash which caused massive disuption to the American econonmy, a depression which lasted until he brought in his New Deal policies and started massive public spening on building Americals infrastructure. Such projects as the Hoover Dam were done under his policies.By the time World War Two started, America was once again thriving and could now ready itself to fight - as it did - against very powerful nations such as Germany and Japan.
I would agree that Franklin Delano Roosevelt (FDR) is probably the most effective, but one has to keep in mind that he was also the only US president to have 3 consecutive terms which kind of skews the effectiveness ratio since he had more time to get things done. I think Bill Clinton, despite the ridiculous Monica Lewinsky scandal and Whitewater, was an excellent president and also accomplished a lot during his two terms.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.