During Franklin D. Roosevelt's term, American was going through its worst economic crisis ever, which had left millions of people unemployed and without their life savings and retirement funding. The most vulnerable (the elderly and the disadvantaged) were affected the most, and consequently, very few Americans had a guaranteed income when they retired.
Being aware of this, Roosevelt established social security under the Social Security Act (1935) in order to provide relief for those people: the act first started giving financial benefits to retirees aged 65 and older and then it was extended to give financial assistance to the elderly in overall, disabled, dependents, unemployed and others disadvantaged Americans.