The sequoia tree, one of three species of redwoods, is among the world’s largest and most enduring organisms. It can grow to 300 feet in height, weigh over 2.5 million pounds (1.1 million kg), and live for 3,000 years. But the majestic sequoia owes much of its size and longevity to what lies below the surface. A twelve- to fourteen-foot deep matting of roots, spreading over as much as an acre of earth, firmly grounds its towering height and astonishing weight.

A redwood’s expansive root system, however, is small compared to the national history, religion, and anticipation that undergird the life…