Considering he rallied the US population into one solidified nation, brought the US out of a serious depression (the stockmarket crash of 1929 sent the US into a depression during the 1930's), defeated the most powerful enemies in the world at that time, and out-produced all of the world's nations in EVERYTHING; he made little to no mistakes worthy of note.
Actually, he made a mistake...In 1942, he signed an executive order that sent 110,000 Japanese Americans to interment camps in remote desert areas because U.S. officials were paranoid about the fact that these people were spies and secretly scheming with Japan (for a possible attack).
I believe the earliest mistake was that once the decision not to reinforce the forces in the Philipines was made, the forces should have been evacuated. The resistance was valiant and proved as a nuisance to the overall Japanese invasion of the Pacific. But to allow the loss of so many valuable and trained personnel was inexcuseable and wrong. I believe the other major blunder was invading Italy from the South. Every Army from Hannibal to Napolean understood Italy is like a boot. You have to invade from the top. With the Mountainous terrain it proved to be the perfect defensive terrain. It proved costly and of little benefit in the overall war in Europe. At Monte Cassino, for example, the allies attacked over 500 German Paratroopers with so many bombers that the Allied soldiers, observing the bombing, felt sorry for the Germans. Over 200 German Paratroopers survived(Amazing since the allies dropped over a ton of bombs for each of the 500 paratroopers defending the position). The 200 paratroopers held the position for several months and were finally dislogged during the 4th attack. The Italian Campaign chewed up numerous experienced US and British Commonwealth Divisions that could never be replaced and did nothing to speed up the end of the war.
Underestimating the enemy at the Battle of the Java Sea; Battle of Savo Island; Battle of Tassafarranga; Battle of Friday the 13th; Battle of the Coral Sea; Battle of Santa Cruz Islands, Battles at Iron Bottom Sound, etc.
avoid mistakes that had led to American involvement in World War I
After World War 1, the United states was faster to get involved in international conflicts. It is a matter of debate whether this change in policy was an improvement.
The US did fight in World War 1, although not from the beginning. Same for World War 2. When both world wars began, they were seen as European squabbles, and there was a strong feeling that the US should make every effort to stay out of them.
that we shall make war together and together make peace
One, Fredenhall, was less than bright in North Africa. Mark Clark I believe advocated going on from Berlin to Moscow ! Patton applauded his men stealing supplies from Bradleys command.
okay i think that they didnt learn fro the past mistakes because their still some problems with some of the states that they had appeasement.
avoid mistakes that had led to American involvement in World War I
World War 2
no they did not
World War 2
After World War 1, the United states was faster to get involved in international conflicts. It is a matter of debate whether this change in policy was an improvement.
The US did fight in World War 1, although not from the beginning. Same for World War 2. When both world wars began, they were seen as European squabbles, and there was a strong feeling that the US should make every effort to stay out of them.
that we shall make war together and together make peace
The country fought in World War I.
One, Fredenhall, was less than bright in North Africa. Mark Clark I believe advocated going on from Berlin to Moscow ! Patton applauded his men stealing supplies from Bradleys command.
US
never drop an atom bomb they regerted it when they saw the destruction that it made in hiroshima an d nagasaki they killed millons