In 1962 the stock market was valued similar to now. In April of that year the market started down similar to the sell-off this year evidently due to President Kennedy's confrontation with the steel industry. The sell-off was brutal. ended in early July, had travelled from DOW 750 to DOW 550, and double bottomed in October. At that time the consensus was that the economy was headed back into the recession of 1960, but much like now there simply wasn't much of a case for recession, but there was a good case for expansion.
The economy doesn't need to be "jump started". That would require artificial stimulus that would initiate inflationary growth, and by inflation I mean its contemporary definition of accelerating prices. If the economy wishes to grow faster than it currently is, then individuals will have to put out more effort. The only way to get that to occur is through lower taxes.
Since that isn't realistic, the possibility of rapid GDP growth is small, but that means a much higher probability of low inflation. It is in such an environment where companies can gradually repair balance sheets and improve earnings. It always means stability in return which yields earnings visibility from which comes the rational admission of higher multiples. This is what occurred in '63.