Located with the counties’ northern border formed by the Ohio River, Greenup County was organized by an act of the General Assembly of Kentucky on December 12, 1803, from Mason County, which included the majority of eastern Kentucky at the time. Three courthouses have served Greenup County. The first courthouse which was made of logs was then replaced by a brick structure in 1811. The county was named after Christopher Greenup who was an American politician who served as a U.S. Representative and the thirs govenor of Kentucky. Though little is known about his early life, the first reliable records about him are documents recording his service in the Revolutionary War where he served as a lieutenant in the Continental Army and a colonel in the Virginia militia. Sitting at 354 square miles of land, it is home to 35,268 residents.