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; a recent 2014 Census estimates the population at 68,364, making it the sixth-largest city in the state. Waterloo is part of the Waterloo – Cedar Falls Metropolitan Statistical Area, and is the more populous of the two cities.HistoryWaterloo was originally known as Prairie Rapids Crossing. The town was established, according to the original researcher as reported by staff of the Grout Museum in Waterloo, near two Meskwaki American tribal seasonal camps alongside the Cedar River. It was first settled in 1845 when George and Mary Melrose Hanna and their children arrived on the east bank of the Red Cedar River (now just called the Cedar River). They were followed by the Virden and Mullan families in 1846. Evidence of these earliest families can still be found in the street names Hanna Blvd., Mullan Avenue and Virden Creek.On December 8, 1845 the Iowa State Register and Waterloo Herald was the first newspaper published in Waterloo.The name "Waterloo" supplanted the original name, "Prairie Rapids Crossing," shortly after Charles Mullan petitioned for a post office in the town. Since the signed petition did not include the name of the proposed post office location, Mullan was charged with selecting the name when he submitted the petition. Tradition has it that as he flipped through a list of other post offices in the United States, he came upon the name "Waterloo." The name struck his fancy, and on December 29, 1851, a post office was established under that name. The town was later called the same, and Mullan served as the first postmaster from December 29, 1851 until August 11, 1854.
