sentences:  Fort Wayne, founded at the confluences of the Maumee, St. Joseph, and St. Marys rivers, was chosen as the county seat in May 1824.According to the 2010 census, the county has a total area of , the largest county in Indiana, of which (or 99.59%) is land and (or 0.41%) is water.As of the 2010 United States Census, there were 355,329 people, 137,851 households, and 90,892 families residing in the county.