Mecca, MissouriMecca is an extinct hamlet in Clinton County, in the U.S. state of Missouri. The site has since been submerged by Smithville Lake.HistoryA post office called Mecca was established in 1898, and remained in operation until 1912. The name possibly is a transfer from Mecca, a holy city in Islam. The populated as about 25 in the early 20th Century.