It wasn't until 1977 that the Congress amended the Federal Reserve Act to include very specific monetary policy objectives. Notably, the Congress established a so-called dual mandate for the Federal Reserve by directing it to foster conditions that would promote the goals of price stability and "maximum" employment.
Over time, maximum employment is only possible when economic growth is sustainable--that is, when economic growth is sufficient to eventually eliminate any gap between level of aggregate demand and the economy's potential to produce. These dual objectives of price stability and sustainable output growth are the cornerstones of the U.S. monetary policy framework.