In 1815 the congress of Vienna made another change in the area and boundaries of Hesse-Darmstadt. Louis secured again a district on the left bank of the Rhine, including the cities of Mainz and Worms, but he made cessions of territory to Prussia and to Bavaria and he recognized the independence of Hesse-Homburg, which had recently been incorporated with his lands. However, his title of grand-duke was confirmed, and as grand-duke of Hesse and of the Rhine he entered the Germanic confederation. Soon the growing desire for liberty made itself felt in Hesse, and in 1820 Louis gave a constitution to the land; various forms were carried through; the system of government was reorganized, and in 1828 Hesse-Darmstadt joined the Prussian _Zollverein_. Louis I., who did a great deal for the welfare of his country, died on the 6th of April 1830, and was followed on the throne by his son, Louis II. (1777-1848). This grand-duke had some trouble with his _Landtag_, but, dying on the 16th of June 1848, he left his son, Louis III. (1806-1877), to meet the fury of the revolutionary year 1848. Many concessions were made to the popular will, but during the subsequent reaction these were withdrawn, and the period between 1850 and 1871, when Karl Friedrich Reinhard, Freiherr von Dalwigk (1802-1880), was chiefly responsible for the government of Hesse-Darmstadt, was one of repression, although some benefits were conferred upon the people. Dalwigk was one of Prussia's enemies, and during the war of 1866 the grand-duke fought on the Austrian side, the result being that he was compelled to pay a heavy indemnity and to cede certain districts, including Hesse-Homburg, which he had only just acquired, to Prussia. In 1867 Louis entered the North German Confederation, but only for his lands north of the Main, and in 1871 Hesse-Darmstadt became one of the states of the new German empire. After the withdrawal of Dalwigk from public life at this time a more liberal policy was adopted in Hesse. Many reforms in ecclesiastical, educational, financial and administrative matters were introduced, and in general the grand-duchy may be said to have passed largely under the influence of Prussia, which, by an arrangement made in 1896, controls the Hessian railway system. The constitution of 1820, subject to four subsequent modifications, is still the law of the land, the legislative power being vested in two chambers and the executive power being exercised by the three departments of the ministry of state. Since the annexation of Hesse-Cassel by Prussia in 1866 the grand-duchy has been known simply as Hesse. Louis III. died on the 13th of June 1877, and was succeeded by his nephew, Louis IV. (1837-1892), a son-in-law of Queen Victoria; he died on the 13th of March 1892, and was succeeded by his son, Ernest Louis (b. 1868). This grand-duke's marriage with Victoria (b. 1876), daughter of Alfred, duke of Saxe-Coburg and Gotha, was dissolved in 1901.