WATERLOO, a village of Belgium, in the province of Brabant, 9½ miles to the south-south-east of Brussels, was the headquarters of the duke of Wellington from 17th to 19th June 1815, and has given its name throughout the English-speaking world to the famous battle fought in its neighbourhood on June 18, 1815. See Napoleon, vol. xvii. pp. 224-25.

WATERLOO, a city and the county seat of Black Hawk county, Iowa, United States, is situated in a rich farming and stock-raising country, on both sides of the Cedar river, which here furnishes a valuable water power. The population in 1885 was 6479, of whom 1048 were foreign-born.

WATERLOO-WITH-SEAFORTH, a watering-place of Lancashire, England, on the Irish Sea, at the mouth of the Mersey, nearly opposite New Brighton in Cheshire, and on the Liverpool, Crosby, and Southport Railway, 4 miles north by west of Liverpool. On account of its facilities for bathing, firm sands, pleasant scenery, and nearness to Liverpool, of which indeed it may now be considered a suburb, it is much frequented during the summer months. It is well and regularly built, and possesses the usual characteristics of a rising watering-place. The population of the urban sanitary district (area 740 acres) was 9118 in 1881.