There are 7 US Post Offices in Lincoln County serving a total of 20,828 residents equating to 2,975 residents per post office. It's estimated that approximately 33,244 packages are handled across the 7 county post offices annually. Lincoln County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 44,828, making it the third-most populated county in the state. Its county seat is Canton. The county was named after Abraham Lincoln, 16th President of the United States. Lincoln County is included in the Sioux Falls, SD, Metropolitan Statistical Area. It is one of the top 10 fastest-growing counties in the United States in terms of rate of population increase, rate of housing unit increase, and many other factors. This is due to the southward growth of Sioux Falls, and the expansion of its suburbs."