Why did the US economy grow in the post-World War II setting?

I would say that the 1950s brought with it unprecedented
economic progress because the war generated enough production as the wheels of industry
moved after a long silence.  The Great Depression had caused industry to shut down and
be invisible.  Yet, the need for war production and consumption helped to restart this
process, causing a high level of material prosperity in America following the war.  At
the same time, the United States was the unquestioned world economic leader.  Europe had
been decimated by World War II, and the new nations that emerged from colonization were
fledgling, at best.  Japan was crippled following the dropping of the atomic bombs, and
China was not a world power.  The Soviet Union was seen as a militaristic adversary to
the United States, but one that could not rival its wealth and material prosperity.  In
the end, this world status also contributed to the expansion of the economy because
there were new markets to be conquered internationally.  The market for exports was
unprecedented as every nation sought to "buy American," for its own nation could not
produce what was needed.  These factors led to the United States' economy expanding so
quickly in the period after the Second World War.