Question

What was the "unprecedented task before us" that required "undelayed action" according to franklin roosevelt?

Answer 1

Franklin Delano Roosevelt (FDR) was in office came into the presidency in 1933, when the United States (and much of the world) was mired in the Great Depression.  The "unprecedented task" was to find a way out of that horrible time of economic collapse.  The task he proposed, requiring "undelayed action," was the implementation of his New Deal programs to spur economic recovery.  I won't go into what all the elements of the New Deal were -- you can look that up quite easily on your own! 

Answer 2

it was dealing with the aftermath of the great depression