Shortly after the sailing of the _Susan_, the Collector of the port of New Orleans detained a steamship with a party of three hundred "emigrants" who were compelled to give up their design of colonizing in Central America. No further attempt was made by Walker until September, 1859, when the guns of a United States frigate were brought to bear upon the steamer _Philadelphia_ at New Orleans, forcibly compelling her passengers to disembark. About the same time Lord Lyons, the British minister, notified the American executive that his Government had resolved to interfere in repelling forcibly any future attempts of Walker against Nicaragua. A squadron of English vessels of war was permanently stationed at San Juan del Norte, while a similarly strong force guarded the Pacific gate. The United States also kept a small fleet in the Caribbean Sea to watch the movements of the exiled president. Napoleon was hardly more of a nightmare to the Holy Alliance than was Walker to the two powerful countries which did him the honour of this surveillance. Meanwhile he was employing his enforced leisure in writing a history of his Nicaraguan career, which he published in the spring of 1860. The book, which was written in the third person, after the style of "Cæsar's Commentaries," is valuable chiefly as a reflection of the author's character. His modesty in alluding to his own exploits is extreme; but he makes no hesitation of avowing his principles as an ardent champion of slavery, devoting many pages to an exposition of arguments which were never logical and are now mournful and ridiculous. That he was sincere is unquestionable. He was a man who would live or die in support of his convictions, and who had too much sincerity of purpose ever to succeed in any undertaking which required duplicity. A proof of his impolitic honesty is found in the fact that at this period of his career he embraced the Catholic religion, a step not calculated to win him favour among either his political friends or enemies. It has been incorrectly stated that he joined the faith on becoming President of Nicaragua; it would have been a wise stroke of worldly policy for him to have done so. But the fact is, that he stoutly maintained his independence of thought until his reason was convinced, even though it might injure him with the clerical party in that country. In Napoleon's place Walker would never have donned the turban nor sought to conciliate the Pontiff, though the empire of a world rewarded the stroke. Empires are neither won nor held by men of such obstinate conscience.