There are 6 US Post Offices in Adams County serving a total of 33,946 residents equating to 5,658 residents per post office. It's estimated that approximately 54,182 packages are handled across the 6 county post offices annually. Adams County lies in northeastern Indiana in the United States and shares its eastern border with Ohio. It was officially established in 1836. The county seat is Decatur. According to the 2010 census, its population was 34,387, an increase of 2.27% from 33,625 in 2000. The county has four incorporated cities and towns with a total population of over 15,000, as well as many small unincorporated communities. The county is divided into 12 townships which provide local services. There are four Indiana state roads in the county, as well as three U.S. Routes and one railroad line."