Mannheim, Or Manheim, a town of the grand duchy of Baden, capital of the circle of the Lower Rhine, situated on the right bank of the Rhine, at the confluence of the Neckar with that river, 43 m. S. S. W. of Frankfort; pop. in 1871, 39,614. It is connected by steamers with Cologne and other places on the Rhine, and by railway with the principal towns of Europe. Goethe has appropriately called it "the pleasant, cleanly Mannheim." The regularity of the buildings, however, gives it a somewhat monotonous appearance. It consists of 11 straight streets, crossed by 10 other streets at right angles, forming 110 regular squares. It is divided into two parts by the great street leading from the palace to the suspension bridge over the Neckar. The principal public squares are the Plankenplatz and the Schillerplatz, where Schiller resided in the house called zum Karlsberg, and which is adorned with fountains, and statues of Schiller, Dalberg, and Iffland. The theatre is a fine building, and in it Schiller's " Robbers " was first acted.

Behind the palace, which contains collections of art, a large library, and a cabinet of natural history, are beautiful gardens, ending in a raised terrace upon the brink of the Rhine (Rheindamm). Along the banks of the Neckar, in the outskirts of the town, are handsome private gardens, and a broad avenue (Plankenstrasse) between the Heidelberg and Rhine gates is planted with trees. In spite of its fine position on two navigable rivers, the trade of the place was formerly unimportant; but of late years, owing to its railway connections, it has become the first commercial town in the grand duchy. The town was founded in 1606, and from 1720 to 1777 it was the capital of the Palatinate. It suffered severely in the thirty years' war, and was almost destroyed by the French in 1688 after a siege of 17 days. It was soon rebuilt, and was strongly fortified in 1699; but in the early part of the present century the ramparts were removed. During the wars of the revolution, the French attacked the town in December, 1794, and occupied it Sept. 20, 1795. During the long siege only 14 houses remained uninjured, and half of the palace was burnt.

By the peace of Luneville (1801), Mannheim was allotted to Baden.