(CNN) -- Crisis begets innovation. In the Great Depression, Americans and Britons developed important new technologies: television, movie sound, refrigeration, automatic transmissions for cars. The supermarket was born, as were the passenger aviation industry and the first franchised food company: Dairy Queen. Big industrial companies such as General Motors and U.S. Steel consolidated their dominance at the expense of weaker rivals. States and the federal government planned and opened the first freeways. Millions of Americans moved off the farms of the South and West to populate California and Florida. In a decade of economic deprivation, in other words, we can begin to see the shape of postwar America: the suburbanized, mass-production economy into which the baby boomers would be born.
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In the midst of today's economic troubles, David Frum sees reasons for hope
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He says America's energy picture is changing fast with new surplus of natural gas
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Americans are returning to urban areas, shortening commutes
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Frum: While health industry has vastly expanded, mental health is a future growth field
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