How was the Natchez Trace used in Eudora Welty's writings?

The Natchez Trace is an old trail in Mississippi that was used for the transportation of slaves, and it was also used for trade and commerce. Many of Welty's stories take place along the almost-five-hundred-mile Natchez Trace from Natchez to Nashville. Welty used the Natchez Trace in her 1940 short story "The Worn Path." In this story, an elderly black woman named Phoenix Jackson travels along the Natchez Trace to Natchez, Mississippi to get medicine to cure her grandson from the effects of lye poisoning. In this story, the Natchez Trail stands for hope, the hope the grandmother has of saving her grandson.
Another example is "A Still Moment," in which Welty imagines a meeting between Lorenzo Dow (an intolerant preacher during the Second Great Awakening), John Murrell (a bandit), and James Audubon (a naturalist) along the Natchez Trace. The lives of the three men converge as they regard a snowy heron in their path. Welty writes:

What each of them had wanted was simply all. To save all souls, to destroy all men, to see and to record all life that filled this world—all, all—but now a single frail yearning seemed to go out of the three of them for a moment and to stretch toward this one snowy, shy bird in the marshes. It was as if three whirlwinds had drawn together at some center, to find there feeding in peace a snowy heron. Its own slow spiral of flight could take it away in its own time, but for a little it held them still, it laid quiet over them, and they stood for a moment unburdened

In this story, the trace stands for life itself. As each character journeys along the trace, he wants to live out his destiny but is instead confronted with an unexpected moment of grace. The trace presents the characters with the unexpected, much as life does.