Germantown, formerly a post borough of Philadelphia co., Pennsylvania, 6 m. N. W. of the state house, Philadelphia, and included since 1854 in the 22d ward of that city; pop. of the ward in 1870, 22,605. It has one main street, about 4 m. long, extending S. S. E. and N. N. W., which is intersected at right angles by several others. It is lighted with gas, is well supplied with water, and is connected with Philadelphia by both a steam and a horse railway. Many retired merchants and wealthy citizens of Philadelphia have here their residences, some of which are of great elegance. Among the public buildings are 21 churches, an academy and other schools, and a bank. There are also a number of extensive manufactories.-Germantown was laid out in 1684 under a grant from William Penn, and settled by Germans, whence its name. It is memorable as the scene of the defeat of the American army under Washington by the British on Oct. 4,1777. Washington, having learned that Gen. Howe had detached a portion of the main division of his army, then at Germantown, determined to take advantage of it to attack his camp. After marching all night, he entered the town about sunrise.

The enemy, who were encamped across the main s.treet at right angles, were taken by surprise, but the morning being dark and foggy, the Americans were thrown into confusion by the many small enclosures of the village, and the British rallied and attacked in turn. Some of the Americans were seized with a panic, and what had promised to be a victory was changed into a defeat.

Washington withdrew in good order, with all his artillery. The British loss was upward of 600; the American about 1,000.