Complex sentence: The first Euro-American traders and explorers arrived in the Tennessee Valley in the late 17th century, although there is significant evidence that Hernando de Soto visited the Bussell Island site in 1540.
Split into simpler sentences: The first Euro-American traders and explorers were recorded as arriving in the Tennessee Valley in the late 17th century. There is significant evidence that Hernando de Soto visited the Bussell Island site in 1540.