Why did the U. S. government use rationing for some foods and consumer goods during World War II?

I have not technically learned about WWII yet, but I can infer that they had to ration foods as the countries they were in war with (and their own country) had to send their men to war, so no one was working on the farms. Resulting in a lack of food and goods.

i confess that there are several parts of this constitution which i do not at present approve, but i am not sure i shall never approve them: for having lived long, i have experienced many instances of being obliged by better information or fuller consideration, to change opinions even on important subjects, which i once thought right, but found to be otherwise. it is therefore that the older i grow, the more apt i am to doubt my own judgment, and to pay more respect to the judgment of others.