Before the year of his return from the peninsula had run out Sir Henry Bulwer was married to the Hon. Georgiana Charlotte Mary Wellesley, youngest daughter of the 1st Baron Cowley, and niece to the duke of Wellington. Early in the following year, on the 27th of April 1849, he was nominated ambassador at Washington. There he acquired immense popularity. His principal success was the compact known as the Clayton-Bulwer Treaty (q.v.), ratified in May 1850, pledging the contracting governments to respect the neutrality of the meditated ship canal through Central America, bringing the waters of the Atlantic and Pacific into direct communication. After having been accredited as ambassador to the United States for three years, Sir Henry Bulwer, early in 1852, was despatched as minister plenipotentiary at the court of the grand duke of Tuscany at Florence. Shortly after his retirement from that post in the January of 1855, he was entrusted with various diplomatic missions, in one of which he was empowered as commissioner under the 23rd article of the treaty of Paris, 1856, to investigate the state of things in the Danubian principalities, with a view to their definite reorganization. Finally he was installed, from May 1858 to August 1865, as the immediate successor, after the close of the Crimean war, of the "Great Elchi," Viscount Stratford de Redcliffe, as ambassador extraordinary to the Ottoman Porte at Constantinople.
In the winter of 1865 Bulwer returned home from the Bosporus, and retired with a pension. He was elected member for Tamworth on the 17th of November 1868, and retained his seat until gazetted as a peer of the realm on the 21st of March 1871, under the title of Baron Dalling and Bulwer of Wood Dalling in the county of Norfolk. Upon the eve of his return to his old haunts as a debater and a politician he had asserted his claim to literary distinction by giving to the world in two volumes his four masterly sketches of typical men, entitled _Historical Characters_. This work, dedicated to his brother Edward, in testimony of the writer's fraternal affection and friendship, portrayed in luminous outline Talleyrand the Politic Man, Cobbett the Contentious Man, Canning the Brilliant Man, and Mackintosh the Man of Promise. Two other kindred sketches, those of Sir Robert Peel and Viscount Melbourne, having been selected from among their author's papers, were afterwards published posthumously. Another work of ampler outline and larger pretension was begun and partially issued from the press during Lord Dalling's lifetime, but not completed. This was the _Life of Viscount Palmerston_, the first two volumes of which were published in 1870. A third volume appeared four years afterwards. Even then it left the story of the English statesman broken off so abruptly that the work remained at the last the merest fragment. It was completed by Evelyn Ashley.