There are 6 US Post Offices in Hamilton County serving a total of 8,812 residents equating to 1,469 residents per post office. It's estimated that approximately 14,065 packages are handled across the 6 county post offices annually. Hamilton County is a county located in the U.S. state Nebraska. As of the 2010 census, the population was 9,124. Its county seat is Aurora. The county was named for Alexander Hamilton, the first Secretary of the Treasury. Hamilton County is included in the Grand Island, NE Metropolitan Statistical Area. In the Nebraska license plate system, Hamilton County is represented by the prefix 28 (it had the twenty-eighth-largest number of vehicles registered in the county when the license plate system was established in 1922)."