Settlement in Monroe County began when Dedrick Pike settled in 1816 where the Cache River enters the White River. The settlement was named Mouth of the Cache, and a post office by that name was opened years later. The community renamed itself Clarendon in 1824 in honor of the Earl of Clarendon. Monroe County was established under the Arkansas territorial legislature in 1829, and the county seat was established at Lawrenceville, where a jail and courthouse were erected. A ferry across the White River was founded in 1836.