sentences:  The county is within a radius of major population centers, including Chicago, Cincinnati, Cleveland, Columbus, Detroit, Indianapolis, Louisville, Milwaukee, and within a one-day drive of one-third of the U.S. population and one-fifth of Canadians.Occupied for thousands of years by cultures of indigenous peoples, Allen County was organized by European Americans on December 17, 1823, from Delaware and Randolph counties; and formed on April 1, 1824, at the Ewing Tavern.The county is named for Colonel John Allen, an attorney and Kentucky state senator who was killed in the War of 1812.