Encouraged by the plaudits from both sides of the Atlantic Cooper wrote another story, “The Pioneers” (1823), which was the first attempt to put into fiction the life of the frontier and the character of the backwoodsman. Here Cooper was in his element, on firm ground, familiar to him from his infancy, but the book was a revelation to the outside world. It is in this work that one of the greatest characters in fiction, the old backwoodsman Natty Bumpo――the famous Leather-Stocking――appeared and gave his name to a series of tales, comprised, in five volumes, which was not finally completed for twenty years. Strange to say, this famous series of books was not written in regular order. To follow the story logically the reader is recommended to read first the “Deerslayer,” next the “Last of the Mohicans,” followed by “The Pathfinder,” then “The Pioneers,” and last “The Prairie,” which ends with the death of Leather-Stocking. The sea tales of Cooper were also suggested by Walter Scott, who published the “Pirate” in 1821. This book was being discussed by Cooper and some friends. The latter took the position that Scott could not have been its author since he was a lawyer and therefore could not have the knowledge of sea life which the book displayed. Cooper, being himself a mariner, declared that it could not have been written by a man familiar with the sea. He argued that it lacked that detail of information which no mariner would have failed to exhibit. To prove this point he determined to write a sea tale, and in 1823 his book “The Pilot” appeared, which was the first genuine salt-water novel ever written and to this day is one of the best. Tom Coffin, the hero of this novel, is the only one of all Cooper’s characters worthy to take a place beside Leather-Stocking, and the two books were published within two years of each other. In 1829 appeared “The Red Rover,” which is wholly a tale of the ocean, as “The Last of the Mohicans” is wholly a tale of the forest. In all, Cooper wrote ten sea tales, which with his land stories established the fact that he was equally at home whether on the green billows or under the green trees. In 1839 Cooper published his “History of the United States Navy,” which is to this day the only authority on the subject for the period of which it treats. He also wrote many other novels on American subjects and some eight or ten like “Bravo,” “The Headsman” and others on European themes; but it is by “The Spy,” the five Leather-Stocking tales, and four or five of his sea tales that his fame has been secured and will be maintained.