From Ohio History Central
Formed on February 14, 1848, Auglaize County was named from a French word meaning "clay-filled water." The county was originally parts of Allen and Mercer Counties.
Auglaize County is located in the western part of Ohio. Its county seat is Wapakoneta, which is the largest city in the county with a population of 9,474 people in 2000. St. Mary's is a close second in population, with just over 8,300 residents in 2000. The county's 402 square miles are predominantly rural, with approximately 116 people living in each square mile. Only 1.7 percent of the county was deemed to be urban. Between 1995 and 2000, the county experienced a 4.5 percent drop in population, a trend that holds true for many of Ohio's more rural counties.
Neil Armstrong, the first man to walk on the Moon, ranks among Auglaize County's most famous residents. The Ohio Historical Society's Neil Armstrong Air and Space Museum is located in Wapakoneta.