The Adelsverein, also known as the Mainzer Verein, the Texas-Verein, and the German Emigration Company, was officially named the Verein zum Schutze deutscher Einwanderer in Texas (Society for the Protection of German Immigrants in Texas). Provisionally organized on April 20, 1842, by twenty-one German noblemen at Biebrich on the Rhine, near Mainz, the society represents a significant effort to establish a new Germany on Texas soil by means of an organized mass emigration. Such German publications as Charles Sealsfield's Das Kajütenbuch, oder Schilderungen aus dem Leben in Texas (1841), Detlef Dunt's Reise nach Texas nebst Nachrichten von diesem Lande (1834), and G. A. Scherpf's Entstehungsgeschichte und gegenwärtiger Zustand des neuen, unabhängigen Staates Texas (1841), which depicted in glowing terms the great personal liberty and the plentiful and productive land to be found in Texas, had served to direct the nobles' attention to the Republic of Texas as the best destination for an increasing German emigration. Accordingly, in May 1842 the association sent two of its members, counts Joseph of Boos-Waldeck and Victor August of Leiningen-Westerburg-Alt-Leiningen to Texas to investigate the country firsthand and purchase a tract of land for the settlement of immigrants. Once in Texas, the two agents discussed colonizing a land grant with President Sam Houston, who, under the provisions of a law passed on February 5, 1842, was authorized to grant entire tracts of land to contractors who would colonize them. Boos-Waldeck and Alt-Leiningen declined Houston's offer of a grant, however, when they learned that it would be in frontier territory west of Austin and still inhabited by hostile Indians. In January 1843 Boos-Waldeck purchased a league of land (4,428 acres) in what is now Fayette County, near Industry, as the base for future colonization, and named it Nassau Farm, in honor of Duke Adolf of Nassau, the patron of the society. Boos-Waldeck remained in Texas a year developing the farm, and in May 1843 Alt-Leiningen returned to Mainz. Though Boos-Waldeck recommended against an immediate large-scale colonization effort, Alt-Leiningen supported such a venture. Accordingly, on June 18, 1843, the association was reorganized as a joint-stock company with a capital stock of 200,000 gulden ($80,000) for the acquisition of more land in Texas. In September the association was approached by Alexander Bourgeois d'Orvanne, a speculator, who with Armand Ducos held a colonization contract for a tract of land west of San Antonio. On March 25, 1844, the association was formally constituted as the Society for the Protection of German Immigrants in Texas with Prince Carl Emich III of Leiningen as president and Count Carl of Castell-Castell as business manager.

The society's goals were both philanthropic and commercial. They included the economic relief of the German proletariat by the direction of emigration to Texas and the establishment of German settlements in Texas, which would supply markets abroad for German industry and promote the development of German maritime commerce. In April 1844, when the society purchased from Bourgeois the colonization rights to his grant, the contract had already expired. Nevertheless, later that month the society dispatched Prince Carl of Solms-Braunfels as general commissioner and Bourgeois as colonial director to Texas to seek renewal of the grant and to prepare for the arrival of colonists. Upon his arrival in Texas in July, Solms learned that Bourgeois could not renew his contract and that the society had acquired from him neither land nor colonization rights in Texas. In the meantime the society had already severed its ties with Bourgeois and, on June 26, 1844, had purchased colonization rights from another speculator, Henry Francis Fisher, who with Burchard Miller held a colonization contract for a tract of land between the Llano and Colorado rivers. The first immigrants disembarked in Texas in December 1844, near Carlshafen (later Indianola), the society's port of entry established by Prince Solms. Since no preparations had been made for settlement on the Fisher-Miller land grant, the immigrants were settled on two leagues of land at Comal Springs that Solms purchased on March 15, 1845, and named New Braunfels after his estate in Germany. On May 8, 1845, John O. Meusebach, Solms's successor as general commissioner in Texas, arrived at Carlshafen; in November he began making preparations for the arrival of 4,000 new immigrants. Fredericksburg, the society's second colony, was established by Meusebach in 1846 near the Pedernales River, where the year before he had bought over 11,000 acres of headright land.

Under Meusebach's administration, from May 1845 to July 20, 1847, when he resigned as general commissioner, the major part of the society's work in Texas was accomplished. Between October 1845 and April 1846 a total of 5,257 German emigrants were brought to Texas. In 1847 five settlements-Bettina, Castell, Leiningen, Meerholz, and Schoenburg-were established in the Fisher-Miller grant on the banks of the Llano River. Under Meusebach's successor, Hermann Spiess, no new settlements were founded.

By the end of 1847 the society was facing bankruptcy. Neither the appointment of Gustav Dresel as special business agent nor the attempt in 1848 to sell the society's holdings to another company was able to save the Adelsverein. Fisher attempted to revive the society under a new name, German Emigration Company. Spiess and Louis Bene, who succeeded Spiess in 1852 as general commissioner, carried on the society's business in Texas under that name until September 1853, when the company assigned all its properties and colonization rights to its creditors. Besides bringing over 7,000 German emigrants to Texas, the chief contribution of the society was to establish Texas as a major goal of subsequent emigration from Germany.

During its brief existence and long after its demise, the Adelsverein was beset by controversy. Though most of its critics acknowledged the philanthropic motives of the society's aristocratic founders-the desire to ease economic pressures on the German proletariat by providing in Texas a refuge for surplus German labor-they were also aware of the society's commercial objectives-assured markets for German industry, a reliable source of raw materials for her factories, and dividends and profits for the society's shareholders. Contemporary criticism of the society came chiefly from two sources: victims of the society's inept planning and mismanagement, who published in Germany letters to friends and book-length exposés of the hardships that they suffered in Texas; and German travelers to Texas who had visited the society's settlements there. The reports of the latter group, which included such writers as Viktor Bracht, Friedrich Kapp, and Ferdinand Roemer, were generally much more balanced than the former in their view of the society's motives and its achievements. Some later accounts, written often by journalists, emphasized the more sensational and anecdotal features of the society's history. Chief among the popular chroniclers was August Siemering, a journalist and Forty-eighter, who even alleged that the Adelsverein had been founded at the instigation of Great Britain as a measure to halt the spread of slavery in Texas and to prevent the annexation of Texas by the United States. Recent historical research supports, however, a mixed view of the society's motives and achievements. As an effort to establish a new Germany in Texas, the venture was a fiasco. The chief causes of its failure were not greed or the mean-spirited parsimony of its members, however, but their lack of business sense, the intrigues of land speculators and some members of the society, the naïveté of the nobles involved, and a lack of trust even in their own officers in Texas.