There are 7 US Post Offices in Carroll County serving a total of 28,005 residents equating to 4,001 residents per post office. It's estimated that approximately 44,699 packages are handled across the 7 county post offices annually. Carroll County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 27,446. The county has two county seats, Berryville and Eureka Springs. Carroll County is Arkansas's 26th county, formed on November 1, 1833, and named after Charles Carroll of Carrollton, the last surviving signer of the United States Declaration of Independence."