Warner's gift was the portrait in low relief — the bas-relief, a sculpted image that rises only slightly from a flat background, exactly the way a face rises from the surface of a coin. He is often credited with helping popularize the form in America. His portrait medallions are quiet and dignified, and they breathe in a way flat profiles rarely do.
His most haunting work began with a friendship. The lawyer and poet Charles Erskine Scott Wood, who had befriended tribes along the Columbia River during army service, feared they were vanishing and urged Warner to record their leaders in bronze. In 1889 Wood brought the sculptor to Portland, Oregon, and introduced him to Chief Joseph of the Nez Perce. The portrait that came out of that meeting was good enough to send Warner west again in 1891 to model more — Cayuse and Nez Perce chiefs, studied from life, real people at a moment when most American art rendered "the Indian" as a type. It is the same instinct that shaped his coin work: catch the specific human face, not the symbol.
That instinct collided with the United States Mint in 1892. The World's Columbian Exposition in Chicago — the great fair marking 400 years since Columbus crossed the Atlantic — needed a souvenir coin to raise money. The Mint's own chief engraver, Charles E. Barber, drew first; the press savaged him, saying his Columbus looked "more a long-haired professor than the celebrated mariner." The fair needed a rescue, and Warner — by then the exposition's director of decorations — was asked to supply one.
What Warner gave them was a complete design, and the reverse was unmistakably his: a caravel — the small, high-sterned sailing ship of Columbus's era, here standing in for his flagship the Santa María — riding above two globes for the two hemispheres, with 1492 below. For the front he worked from the fair's own badges, which carried a profile of Columbus facing right. On September 23, 1892, fair leaders and Mint officials settled it: the badge profile for the obverse — the "heads" side — and Warner's caravel for the reverse.
Here is the twist that makes Warner a kind of ghost. By Mint rule, only Mint engravers could cut the working dies — the hardened steel stamps that strike the design into each blank. So Barber adapted the obverse and signed it with his "B" near the neck, and his assistant George T. Morgan reworked the ship from photographs and tucked his "M" into the rigging. The coin the public bought — and that catalogs still credit to Barber and Morgan — was built on Warner's design, wearing two other men's initials. The result, the Columbian half dollar, became the first commemorative coin the United States ever struck, and the first U.S. coin to portray a real historical person rather than an allegory of Liberty.
Warner did not have long. In 1895 he won the kind of commission a sculptor dreams of: bronze doors for the new Library of Congress in Washington. He had finished three tympanums and one door when, on August 14, 1896, he died of injuries from a bicycle accident in New York's Central Park. He was 52. The sculptor Herbert Adams completed the rest.