Groton ,.I. A town of Middlesex co., Massachusetts, on Nashua and Squannacook rivers, 30 m. N. W. of Boston and 13 m. W. of Lowell; pop. in 1870, 3,584. Since the census the town of Ayer has been taken from it. Four railroads, viz., the Worcester and Nashua, the Fitchburg, the Stonybrook, and the Peterborough and Shirley, intersect at Ayer Junction (formerly Groton Junction). Groton is the seat of the Lawrence academy, which was incorporated in 1793, and owes a liberal endowment to the munificence of the Lawrence family, who are natives of this place. The academy has a library of 2,500 volumes and an endowment of $80,000. In 1872 the number of instructors was 7, and of pupils 147, of whom 92 were males and 55 females. The town contains several saw and grist mills, manufactories of agricultural implements, paper, and leather, and 10 public schools. II. A town of New London co., Connecticut, on Long Island sound, at the E. side of the mouth of Thames river, and opposite New London; pop. in 1870, 5,124. It is on the Stonington and Providence railroad, the principal village being 12 m. W. of Stonington, and 62 m. by rail S. W. of Providence. There is a good harbor, and the town is interested in the coasting trade, ship building, and the fisheries.

A considerable export business is carried on with New York. Mystic and Pe-quonnock rivers flow through the town to Long Island sound, and supply valuable motive power, which is employed in running cotton mills, etc. There are founderies of brass and iron, manufactories of britannia ware and carriages, two granite quarries, and 11 public schools. The town contains a United States naval station and five post offices, viz. : Groton, Centre Groton, Poquonoc Bridge, Noank, and Mystic River. Groton is the site of Fort Griswold, memorable for the massacre of an American garrison at the time of the destruction of New London and Groton by the British troops under Benedict Arnold, Sept. 6, 1781. The British having captured the fort after a desperate resistance, the American commander, Col. Led-yard, surrendered to the officer of the detachment, and was immediately killed with his own sword, most of his men being also butchered; 85 of the Americans were killed and 60 wounded. A granite monument to commemorate this event was erected in Groton in 1830.