But Astor was no drug dealer. He’d sold the Chinese furs. Importing silks and spices in return, he’d multiplied his profits. And with those profits, he’d made the simplest investment in the world: he’d bought Manhattan land. He didn’t develop it, usually—he just bought it, leased it, or sold it on. As the city was rapidly expanding, the land values shot up. He’d quietly continued the process, become a revered city elder, the patron of Audubon, of Edgar Allen Poe, and even founded the Astor library. Last year, he had died worth twenty million dollars, the richest man in America.

“You think the railroad business could be that big?” Hetty asked.

“I do,” said Frank. “When I was a boy, my father took me to the opening of the Erie Canal. That canal alone transformed the shipping of grain and caused a huge expansion of places like Albany. Given time, the new railroads will far exceed what the canals accomplished—they’ll change the whole continent. Unlike canals, they’re easy to build, and the speed at which freight, and people, can travel is going to increase by leaps and bounds. Land prices are going to rise all the way along the new railway lines, if you can just figure out the right places. There’ll be opportunities to invest in the railroads themselves, as well.”

“Let’s look at the maps, then,” said his wife, with a smile.

She’d always been his partner, right from the start. Always supported him, whatever he wanted to do, joined in his interests and enthusiasms. Once, when someone had asked him when he’d first been sure he wanted to marry Hetty, to their great surprise they’d received the answer: “It was the Croton Aqueduct that did it.” But it had been perfectly true.

If the old water supply of New York had been inadequate for decades, the city’s eventual solution was magnificent. Forty miles to the north the River Croton, which ran into the Hudson, was dammed to make a huge reservoir. From there, water was carried south in a covered canal until it crossed by bridge over the Harlem River onto the north end of Manhattan. Passing over two more high aqueducts on the way, it flowed down through conduits into a thirty-five-acre receiving reservoir, which extended between Eighty-sixth and Seventy-ninth Streets on the city plan. Another five miles of conduits and pipes brought water from the receiver to Murray Hill, where the distributing reservoir, a splendid building just below Forty-second Street, and which looked like a fortress, held twenty million gallons.

The whole thing was a masterpiece of engineering, and it hadn’t surprised Hetty in the least that, just before its completion in 1842, while they were still courting, Frank had said that he wanted to inspect every inch of it. What astonished him, and everyone else, was that she cheerfully announced: “I’m coming too.”