In August, on the dubious pretext of having just learned that a copy of Green's book could be found on the shelves of the Library of Congress, Houston rose on the floor of the Senate to attack the author and his book. No doubt his motives for publicly defaming a book almost a decade after publication had more to do with Green's delivery of the keynote speech at ground-breaking ceremonies for the Texas link of the railroad at Tyler a month earlier. The book, Houston noted, had slandered him no less than 117 times, and after painting a highly unsavory picture of Green's career in Texas, he denounced the work as an "unclean thing, which should never defile a library."71

Six months later, Green retaliated to the speech with the publication of a sixty-seven-page pamphlet, which he distributed both to members of the Senate and to Houston's enemies throughout the United States. In this rambling, unfocused diatribe, Green gave full vent to his rage, determined not only to respond to Houston's charges, but to provide a compendium of the Texas senator's crimes and shortcomings. The transgressions of Benedict Arnold and Judas, he stated unequivocally, paled beside Houston's "life-time of iniquity."72 Eager to have the last word, Houston addressed the Senate again a few days later to respond to Green's pamphlet, declaring, "I would not advise any decent and respectable person to touch him with a fifteen-foot pole, unless he had gloves upon his hands of double thickness, and then he should cast away the pole to avoid the influence of the contaminating shock."73 This unseemly exercise in character assassination had by this time overshadowed Green's involvement with the Atlantic and Pacific Railroad, which soon foundered in a maze of legal maneuvering.74 Subsequently reorganized, the project was taken over by new investors, who managed to build a few miles of track in East Texas before the outbreak of the Civil War.

By 1856 the peripatetic Green had turned his attention to an entirely new money-making scheme: the development of a seaport defense system, which he planned to sell to the U.S. Navy. The device called for a series of cylindrical mines, designed to explode on contact with enemy ships, which could be attached to a special boom and laid at the mouth of a harbor. Green believed strongly enough in the project to acquire two-thirds ownership of the device, but officials at the Navy Department did not share his enthusiasm. After examining models and blueprints of the apparatus, a navy engineer reported that the mines would do little damage to enemy ships, and the boom itself would be too heavy, causing it to pull away from its moorings in rough seas. In short, the report concluded, the contraption was impractical and totally inadequate for harbor defense.75

As the storm clouds of the secession crisis began to gather at the close of the decade, Green abandoned his entrepreneurial efforts, taking up the more sedentary life of a planter at his family home, Esmeralda, in Warrenton, North