There are 4 US Post Offices in Putnam County serving a total of 4,658 residents equating to 1,165 residents per post office. It's estimated that approximately 7,435 packages are handled across the 4 county post offices annually. Putnam County is a county located in North Central Missouri. As of the 2010 census, the population was 4,979. Its county seat is Unionville. The county was organized February 28, 1845 and named for Israel Putnam, a hero in the French and Indian War and a general in the American Revolutionary War. Putnam County was established February 28, 1845 from parts of Adair and Sullivan counties. The following year a portion of Putnam was removed to form of Dodge County. Both Putnam and Dodge extended nearly nine miles further north until a 1851 ruling by the Supreme Court on a border dispute with Iowa assigned the contested land to Iowa. Both counties were left with less than the statutory minimum area for a county as set by the state legislature, so Dodge County was dissolved and its area added to Putnam. In its early years, the county seat changed frequently, often with contentious debate. Putnamville, Bryant Station (both no longer in existence), and Hartford all served until a central location called Harmony, later renamed Unionville, was chosen. In the 1860 U.S. Census Putnam County had 9,240 residents, with eighteen sawmills and three flour mills. Coal had been an abundant since its earliest settlement. Following the arrival of the Burlington & Southwestern Railway in 1873, coal mining became a major industry, especially in the east of the county. At one time three railroads crossed Putnam county: the Chicago, Milwaukee and St. Paul; the Chicago, Burlington and Quincy; and the Iowa and St. Louis. Putnam County lost over two-thirds of its population between the years 1900 and 2000 (see census data below), when the United States changed from a rural to an urban country."