Why did president franklin Roosevelt call a special session of congress

During his presidency, Rooselvelt called three times for a Special Session of Congress:

The two firsts calls (in 1933 and 1937) were related to the implementation of the New Deal, as the package of measures designed to combat the harsh situation of the US economy. The New Deal was based on Keynesian economics that identified, as the major cause of the Great Depression, the extremely low aggregate demand figures. This solution aimed to boost demand figures by directing large sums of public money to the creation of job positions for the large unemployed sectors of popualtion, so that they could start to earn a salary and to demand products again. Large sums of money were pumped into public works (roads, constructions, etc). The third call took place in 1939 in order to define the Neutrality legislation that would keep the US away from participating on WWII that started in Europe on that year. Finally, in 1942, the neutrality strategy was changed, after Pearl Harbor and other attacks, and the US ended up intervening in the conflict, in the side of the Allied powers.