As the United States was recovering from the social and political turmoil of the Civil War, a rivalry emerged in the nascent field of American Paleontology. Othniel Charles Marsh and Edward Drinker Cope, former friends turned competing paleontologists, began scouring the American West for prehistoric fossil deposits in the hopes of discovering unknown species from the past. While the two scientists came from different backgrounds, their common passion for paleontology and mutual disdain for each other fueled their ambition, ultimately leading to the discovery of over a hundred new species in America. At the same time, their bitter rivalry damaged their reputations and left the two almost penniless at their deaths.

The term "paleontology" was coined just nine years before Othniel Charles Marsh's birth October 29, 1831 on a farm in Lockport, New York. At the time, it might have seemed hard to predict Marsh's future as one of America’s leading paleontologists. His mother died when he was three years old, and his father's only ambition for his son was that he become a field hand on the family farm. Marsh showed interest in science as a boy, and with the encouragement and financial backing of his millionaire uncle George Peabody, he was able to escape the family's farm, excelling first at Phillips Academy, and then at Yale, and later as a graduate student in Germany.

Edward Drinker Cope, born nine years after Marsh on July 28, 1840 to a wealthy family in Pennsylvania, took an immediate liking to natural history as a child and attended classes at the Academy of Natural Sciences in Philadelphia. At 18, Cope published his first scholarly article while working as a researcher at the Academy of Natural Sciences. In 1863, to avoid Cope being drafted into the Civil War, Cope's father sent his son to Germany to study natural history. There he met graduate student O.C. Marsh.

Upon returning to the U.S. in 1864, Cope and Marsh maintained their amicable relationship. Cope named an amphibian fossil Ptyonius marshii, after Marsh in 1867, and, in return, the next year Marsh named "a new and gigantic serpent from the Tertiary of New Jersey" Mosasaurus copeanus.

Marsh's reciprocal gesture, however, was far more complicated. In 1868, in an act of friendship, Cope had shown Marsh around a fossil quarry in Haddonfield, New Jersey. Behind Cope's back, however, Marsh made an agreement with the quarry owner to have any new fossils sent directly to him at Yale. Cope would later describe the act as the beginning of the end of their friendship.

Simultaneously, in 1868, Cope rushed to publish findings on a new species of plesiosaur that had been shipped to his office from an Army surgeon in Kansas. He called the new creature Elasmosaurus platyurus. In his reconstruction of the extinct animal, Cope mistakenly reversed the vertebrae, positioning the skull at the end of the tail. On a visit to the Academy of Natural Sciences to inspect the reconstruction, Marsh supposedly was the first to point out Cope's blunder, an error that was soon confirmed by Joseph Leidy. Embarrassed, Cope quickly published a correction, and even tried to purchase all known copies of the American Philosophical Society journal with the error, but the damage had been done. Of the incident, Marsh later wrote, "when I informed Professor Cope of it, his wounded vanity received a shock from which it has never recovered, and he has since been my bitter enemy." 

The rivalry between the two paleontologists intensified as they each headed west to hunt for fossils. Marsh divided his attention between recovering as many fossils as possible in the yet unexplored region and his constant dread that Cope might retrieve a share of bones of equal quantity or interest. Marsh even went so far as to have spies track Cope's progress, referring to Cope by the codename "Jones."

For his part, Cope competed by rushing to publish his findings in academic journals, a practice paleontologist Bob Bakker calls "taxonomic carpet-bombing". Going further, in an effort to ensure his work got recognized, Cope purchased The American Naturalist journal in 1877. Between 1879 and 1880, Cope published 76 academic papers, a small percentage of the 1,400 articles he would write over the course of his lifetime, making him one of the most prolific authors in American scientific history. In just a few years, the number of known dinosaur species jumped from a small handful to more than a hundred.

Marsh was determined to put his rival out of business. In 1882, he used his superior connections and political skills in Washington, D.C. to become chief paleontologist of the newly-formed U.S. Geological Survey. This gave Marsh access to an immense amount of institutional support; not only did he have access to federal funds, but he gained a significant amount of political power. He set about isolating Cope, cutting him off from the government funding which both men had relied on over the years, especially for the preparation of expensive, illustrated volumes reporting on their fossil discoveries. A desperate Cope attempted to make up for the loss in a silver mining venture in New Mexico. Instead, he lost everything.

By 1890, separated from his wife and child, Cope was living alone in a small Philadelphia apartment. His fossil collection was all he had left. Marsh then made a fatal mistake. He attempted to take Cope's fossils, claming they had been collected with federal money and thus belonged to the government. Cope fought back, producing evidence that he had paid for almost all of his collecting out of his own pocket. Then, he set out to destroy Marsh.

For years, Cope had been collecting information -- records of nefarious, underhanded dealings and accusations of scientific impropriety -- to use against Marsh. He turned them over to a freelance journalist at The New York Herald, an eager purveyor of scandals. The headline, "SCIENTISTS WAGE BITTER WARFARE," set off a firestorm. The public battle lasted for two weeks, as the professors fired accusations at each other. Marsh and his allies in the U.S. Geological Survey were publicly accused of corruption, incompetence and misuse of government funds. Congress investigated and eventually slashed funding for the Survey, eliminating the department of paleontology along with Marsh's position, power, and most of his income. As a final indignity, the Smithsonian demanded that Marsh turn over a large part of his own fossil collection, some of which had, in fact, been collected with government funds.

The paleontologists' flare for public slander had damaged both of their reputations. Cope was unable to find a bidder who could afford his entire fossil collection, which he had spent over 20 years developing. Finally, a fellow at the American Museum of Natural History bid $32,000 for part of the collection. In 1897, Cope became ill and died at 56.

In 1899, at the age of 67, Marsh died of pneumonia with just $186 in his bank account. Over 80 tons of Marsh's personal collection of fossils was acquired by the Smithsonian, but Marsh left the bulk of his collection to the Peabody Museum of Natural History at Yale.

While the feud between Cope and Marsh consumed the scientists' lives and damaged their careers, the amount and quality of bones they each collected became the foundation of paleontology in America. Cope left behind 13,000 specimens, and Marsh's comparable collection proved to be "the best support of the theory of evolution," according to a personal letter from Charles Darwin himself.