father made him devastating to his pupils: the day after he lost a crew race—he loved to row—the girls showed up for class wearing crepe mourning bands. He was in turn devastated by one of the students, and in 1860 the dark, lovely, patrician Anna Russell became his wife.

Now he began his lifelong study of marine invertebrates; North American Acalephae and Embryology of the Starfish , illustrated with hundreds of his own drawings, both appeared in 1865. He took no part in the Civil War. “I am ashamed and have been ashamed any longer to stay at home,” he wrote, “and yet what is to become of father, if I go?” He had been helping with the museum the elder Agassiz had long worked to establish, and “father will go to thunder if I don’t stay and hold on to his coat tails.” He knew that his magnetic, grandiloquent father had little trouble raising money but no ability whatever to hold on to it. If things were to proceed at all smoothly, someone in the family would have to get rich.

SO IT WAS that in 1866 Alexander left the work he liked best and journeyed to the wild, steep landscape on the Michigan shore of Lake Superior where a man named Edwin Hurlbert had opened the Calumet copper mine. Hurlbert was the perfect picture of the mid-nineteenth-century entrepreneur: brave, hardy, independent, willing to take on enormous challenges; the only trouble was that he was deeply stupid about mining. Alexander looked around, saw the land was rich, “but with the kind of management many of the mines have had, then even if the pits were full of gold, it would be of no use.” He borrowed a little money, bought land south of Calumet, organized the Hecla Mining Company, and went to work. He was thorough, diligent, and a good boss to the miners. Soon he became treasurer of the Calumet and Hecla mines. His wife and infant son George came to live with him in a log cabin surrounded by country so raw that Anna would strap a revolver to her waist before taking George for a walk. Alexander persevered through a thousand reverses, both small (Hurlbert was jealous of everything he did) and great (the gauge of the locomotive brought in at enormous trouble and expense was an inch too narrow for the track that had been laid).

By 1868 he’d done the job. It would be a year before Hecla paid its first dividend, but Agassiz believed that, thereafter, he would have to come west only for brief visits. He was right. Hecla eventually produced more copper than any mine on earth and paid its investors bigger dividends than any metal mine in history. Alexander had permanently damaged his health, but he was free now to devote his efforts to his work on marine biology, Revision of the Echini .

In 1873 he wrote, “Everything seems so prosperous that I feel as if some of us would have to pay a heavy penalty, by and by, for all our happiness. …” That winter Louis Agassiz suffered a stroke and died a week later. Young Anna Agassiz caught pneumonia while caring for her stricken father-in-law and died eight days after that. “Few young men,” wrote Alexander, “have reached my age and have attained … all their ambition might desire, and yet the one thing which I crave for … is wanting. How gladly would I exchange all that I have for what I have lost.”

He never remarried. In time he made a comfortable widower’s life for himself, looked after by his beloved stepmother and giving dinner parties at Newport that were famous for their conviviality and good food. But until the end of his days he could never bear to make the briefest mention of Anna’s death. “I feel as if I were acting a lie,” he said once, “but it is a harmless one which I must make up my mind to keep up for many a long year.”

HE WAS by no means idle. He raised the funds to complete his father’s Museum of Comparative Zoology—$1,215 came in from the Calumet miners—and embarked on a series of exploratory voyages that would occupy the rest of his life. Here, too, in his oceanographic studies, he honored the memory of his father. The elder Agassiz could never bring himself to accept Darwin’s theory of evolution, holding to the end that only God could bring about new species. Alexander knew better than to attack the Englishman on that, but for a quarter of a century he kept up a relentless drumfire against Darwin’s theories of atoll formation.

During those years he never ceased his researches, and they won him honor after honor: England awarded him the Victoria Research Medal; France made him an Officer of the Legion of Honor; and before his death in 1910 the house of Hohenzollern overlooked the insults he had offered it a lifetime before to make him a Knight of the Order of Merit of Prussia.