In September, 1848. he returned with a body of followers to Baden, and stirred up a second insurrection. After his defeat at Stauffen, he was arrested, 25 September, 1848, and on 30 March, 1849, was condemned to five years' solitary confinement for high treason. He was taken to the Bruchsal penitentiary on 12 May, but on the following day the revolutionists took possession of the government, and set him free. He went to the fortress of Rastadt, and stirred the soldiers of the garrison to revolt and fight on the side of the people against the Prussians. He was the leader of the Republican party in the constituent assembly. When that body was dissolved after the victory of the Prince of Prussia over the armies of Baden and the Palatinate, Struve again escaped into Switzerland. The authorities, after two months, expelled him from that country. He went to France, and afterward to England, and in 1851 emigrated to the United States. He edited the "Deutsche Zuschauer" in New York city, but soon discontinued its publication because of insufficient support. He wrote several novels and a drama in German, and then undertook, with the assistance of his wife, the composition of a universal history from the standpoint of radical republicanism.

In the beginning of the civil war he entered the volunteer service as an officer in the 8th New York regiment, but retired when Prince Felix Salm Salm succeeded Louis Blenker as its colonel. In 1863 he returned to Germany, availing himself of a general amnesty, and thenceforth he devoted himself to literary pursuits and lectured on phrenology in Stuttgart, Coburg, and Vienna. He was appointed United States consul at Sonneberg in 1865, but the Thuringian states refused to issue his exequatur. His publications include "Politische Briefe" (Mannheim, 1846); "Das offentliche Recht des deutschen Bundes" (2 vols., 1846); "Grundzuge der Staatswissenschaft" (4 vols., Frankfort, 1847-'8) ; " Geschichte der drei Volkserhebungen in Baden" (Bern, 1849) : "Weltgeschichte" (6 vols., New York, 1856-'9; 7th ed., with a continuation, Coburg, 1866-'9) ; "Das Revolutionszeitalter" (New York, 1859-'60); "Diesseits und jenseits des Oceans" (Coburg, 1864-'5); " Kurzgefasster Wegweiser ftir Auswanderer" (Bamberg, 1867) ; "Pflanzenkost die Grundlage einer neuen Weltanschauung" (Stuttgart, 1869); " Das Seelenleben, oder die Natur-geschichte des Menschen" (Berlin, 1869); and "Eines Fiirsten Jugendliebe," a drama (Vienna, 1870).--His wife, Amalie, died on Staten island, New York, in 1862, was the author of "Erinnerungen aus den badischen Freiheitskatmpfen " (Hamburg, 1850) ; and "Historische Zeitbilder " (3 vols., Bremen, 1850).