The American Spirit has always been about opportunities, optimism, exploration and freedom.
Since Europeans landed on the shores of the 'New World' the dream was explore the land, move west, make money, live freely, and have a better life.
When the United States completed the Inter-state highway project, it was a new era in the connectivity of the States from the Pacific to the Atlantic.
It was a historical moment, one, only seen before with the trans-Atlantic railway system.
The American highways are a symbol of the American dream of moving through the continent, exploring the country, freedom to go anywhere and make a better life.