what is a waterloo
Waterloo, IA. Online Offers. Waterloo is a city in and the county seat of Black Hawk County, Iowa, United States. As of the 2010 United States Census the population decreased by 0.5% to 68,406. Waterloo is part of the Waterloo â Cedar Falls Metropolitan Statistical Area, and is the more populous of the two cities. Waterloo was originally known as Prairie Rapids Crossing.