Plattsburgh, a town and village of Clinton co., New York, capital of the county, situated on Cumberland bay, an inlet of the W. shore of Lake Champlain, at the mouth of the Sara-nac river, 145 m. N. of Albany and 22 m. S. of the Canada line; pop. of the town in 1870, 8,414; of the village, 5,139. The village is lighted with gas, has a good fire department, •and is supplied with water from a reservoir fed by springs, 7 m. distant. The principal public buildings are the custom house and post office, court house and jail, and the high school building recently erected at a cost of $40,000. Plattsburgh is a United States military station, the barracks being situated about a mile S. of the village. It is a station on the New York and Canada railroad, a branch of which extends to Au Sable Forks, 20 m. S. W., bringing the village into easy communication with the Adirondack wilderness. The wonderful Au Sable chasm is 12 m. distant. Plattsburgh is the port of entry of the Champlain customs district. The value of imports into the district for the year ending June 30, 1874, was $2,176,784; of exports therefrom, $1,076,111. The number of entrances from Canada was 1,707, tonnage 136,870; clearances, 1,798, tonnage 145,612; clearances in the coastwise trade, 993, tonnage 68,098; belonging in the district, 849 vessels, with an aggregate tonnage of 58,268, of which 769 of 52,487 tons were canal boats.

Large quantities of logs are floated down the Saranac river at high water, and the product of 52 iron bloom forge fires is brought to Plattsburgh for shipment, the ore being obtained from mines on the Saranac and Au Sable and their tributaries. The village contains a foundery, two machine shops, a bloom forge, planing mill, shingle mill, woollen factory, four saw mills (producing annually about 25,000,000 ft. of lumber), and several large carriage and furniture manufactories. It has two national banks, a savings bank, three good hotels, five public school houses besides the high school building, two weekly newspapers, a public library containing 1,000 volumes, and six churches. - Plattsburgh was settled in 1785, principally from Long Island and Dutchess county. One of the first naval battles of the revolution was fought on Lake Champlain off this place, Oct. 11, 1776, Benedict Arnold commanding the American fleet. The Royal Savage, Arnold's supply ship, which was sunk early in the battle, is still visible at low water.

During the war of 1812 Plattsburgh was the headquarters of the United States forces on the northern frontier, and Cumberland bay was the scene of an engagement between the American and British flotillas, Sept. 11, 1814. (See Champlain, Lake.) The place has been devastated by two remarkable fires, in 1849 and 1867; each time the main business portion of the village was destroyed.