There are 26 US Post Offices in Jefferson County serving a total of 438,907 residents equating to 16,881 residents per post office. It's estimated that approximately 700,545 packages are handled across the 26 county post offices annually. Jefferson County is a county located in the U.S. state of Kentucky. As of the 2010 census, the population was 741,096. It is the most populous county in Kentucky and is more than twice as large as the second most populous, Fayette. The county was formed in 1780 and named for future President Thomas Jefferson, who was Governor of Virginia at the time. In 2003, its government merged with that of its largest city and county seat, Louisville, forming a new entity, the Louisville/Jefferson County Metro Government (official long form) or Louisville Metro (official short form). Whenever possible, the metro government generally avoids any self-reference including the name \"Jefferson County\" and has even renamed the Jefferson County Courthouse as \"Metro Hall\". Jefferson County is the anchor of the Louisville-Jefferson County, KY-IN Metropolitan Statistical Area."