The majority of Americans participate in a complex national and global food system. Most of their food production and processing occurs far away from where they live and buy their groceries. It was not always this way; prior to World War II most of the agricultural production and marketing systems in the United States had a strong local or regional base, and farms supplied that base with a wide variety of crop and livestock products. Changes occurred rapidly after World War II as agriculture became increasingly specialized.
The introduction of new technologies allowed many states to focus their agricultural production on just a few crop and livestock enterprises in order to have an economic competitive advantage. As late as the 1950s there were 25 to 30 different crop and livestock commodities produced on at least one percent of the farms in the Midwest; by the end of the 1990s there were only 15 or fewer commodities produced on at least one percent of the farms in the Midwest. Today, most of the food for sale in grocery stores comes from farms in states or countries through a system that is, for the most part, invisible to the consumer.
I remember teaching first grade in an inner city in the 80s. I'd ask the kids where milk comes from. "The store!" they would invariably answer. Our field trip to the apple orchard was a revelation to them. They literally did not make the connection of food and the land until that moment when they saw the apple hanging from the tree. All they ever saw was cellophane wrapped items in a mini mart. The food production chain was invisible to them until the last stop.
Using fresh produce as an example, carrots grown in the San Joaquin Valley in California and transported to supermarkets in Des Moines, Iowa will travel approximately 1,400 miles. Chilean grapes transported by ship and truck to Des Moines, Iowa markets travel 7,270 miles. That's too many miles! We don't have the oil anymore to indulge in such extravagances as off season carambola fruit!
We need to grow our own food again. 'But I don't have acres of land!' you protest.
Almost half of all vegetables grown in the United States in 1943 came from victory gardens. A poster campaign ("Plant more in '44!") encouraged the planting of Victory Gardens by nearly 20 million Americans. Victory gardens were planted in backyards and on apartment-building rooftops, with the occasional vacant lot "commandeered for the war effort!" and put to use as a cornfield or a squash patch. After WWII though we reverted to trucked-in agricultural products until by the 1970s we relied on exotic foodstuffs as a measure of our wealth and position in the world.
And then there's this guy, sustaining himself and his family with food grown on his California suburban housing lot no bigger than one tenth of an acre... It CAN be done. And it should be. Soon will will have to. Get ready now, you will be happy you did.