While our cultural imagination no longer fixates on the Great War or the Western frontier, the idea of the perfect couple (and, especially, the perfect wife) is still alive and well.
Even in Texas, with its tradition of lenient gun laws and frontier justice, the idea of teachers' taking guns to class has rattled some people and sparked a fiery debate.
A powerful and defining impulse in American literature of the 19th and 20th century is the "frontier thesis" – the idea that the essential quality and worth of Americanness is most clearly demonstrated in the struggle to push civilisation westward, from "shining ocean to shining ocean".
"To make a work that measures up to the scale of the Cour d'Honneur, to create a piece with a visual artist like Miquel in another unique space — these things have pushed me toward new frontiers, the very idea for the festival that we kept coming back to at the outset".
"Countries founded on a powerful frontier mentality have this idea of limitless nature than can be endlessly extracted," she said.
Speaking of the world, the next frontier for clean-energy ideas is clear: developing countries, and particularly China.
"A Frenchman, a Tibetan, an African-American — together we suggested a world that might lend itself to Anselm Kiefer's idea of frontiers," he said.
Reading on an airplane one day, he came across a squib of an idea about the frontier fur trapper Mr Glass and his incredible story of survival.
There's a sense in which Frederick Jackson Turner's 1893 argument about how the idea of the frontier shaped American history can apply to the entire modern project.
It is harder and more important to extend that idea to the frontier, where anonymous ranchers are doing most of the deforesting, but there is progress here, too.
