I would like to have been in St. Louis toward noon on September 23, 1806, when Lewis and Clark and their men returned from the Pacific. Word had preceded them, and a mixed crowd of French, Spanish, blacks, Indians, Canadians, and Americans, some in broadcloth and some in buckskin, were waiting when they pulled into the boat landing at the levee. Gunfire, cheers, excitement.

We in St. Louis knew by then that our country had increased its size majestically by purchasing the Louisiana Territory. We knew—some of us at least—that beyond the Rockies was a river called variously the Oregon and the Columbia, to which the otter trader Robert Gray had established a claim for the United States—a claim Great Britain disputed.

But what did it all mean ? Well, we’d know now. We’d hear it from those burned and bearded homecomers who’d crossed endless plains black with buffalo and had gaped at great, grizzled bears they could hardly believe in; who’d followed the trails of unnamed tribes through deep forests of evergreens, past snowy peaks incalculably high, on and on into what became the American dream of the West. For the first time we could feel it in our bones: our only bound was the western sea. We were truly a continental nation.