How do the U.S. government and the Federal Reserve counteract the severity of a recession?

Answer 1

Printing more money.
Of course, this lowers the value of the dollar.
But Hey, there's more of it to go around and to hand out in ridiculous gov. programs.

Not that it's a good economic policy, but what policy of the US government has really been good in the last, oh, 75 years or so?

Answer 2

Via fiscal and monetary policy, respectively.

The Congress can 'stimulate' the economy by increasing spending. For instance, durring the Great Depression, numerous public works projects like dams and the Golden Gate Bridge were undertaken to create jobs. That's fiscal policy.

The Fed is in charge of monetary policy. It can lower interest rates or buy back treasury securities for cash, to 'add liquidity' to the banking system.

Either can help reduce the severetity of a recession - though, if not used with restraint, they can also cause runaway inflation, as happened in the 70s.