wages. When the United States Colored Troops were founded in 1863, many men from the colony enlisted. A corps of Northern teachers was sponsored by the American Missionary Association, and they taught hundreds of students of all ages at the colony. Geological formation and Pre-Columbian settlement See also Roanoke People and Croatan People. The North Carolinian Coast began to shape into its present form as the Outer Banks Barrier Islands. Previously the North Carolina Coast had extended 50 miles eastward to the edge of the continental shelf. The melting of Northern Hemisphere Glaciers at least 14,000 years ago caused sea levels to rise. The Outer Banks and by extension the land of Roanoke Island began to stabilize around 6,000 B.C. Roanoke Island was originally a large dune ridge facing the Atlantic coastline and therefore is not a barrier island contrasting with the Bodie Island that exists 2 miles to the east. Archaeological discoveries at the Tillett site of Wanchese, North Carolina, have dated the human occupation of Roanoke Island's land at 8,000 B.C. At the time Native Americans across North America were developing in the Archaic Period. Archaeologists discovered that the land of Roanoke Island was part of the Mainland when it was first inhabited by the first Native Americans. For thousands of years the development of Native Cultures on Roanoke Island corresponded with cultures occurring in the Coastal Plain of North Carolina. Around the year 400 AD the area experienced environmental transformation. The sand dune of Roanoke became disconnected from the mainland by water, and inlets in the Outer Banks turned fresh water sounds (lagoons) into brackish ecosystems, the land termed Roanoke Ridge became Roanoke Island. From approximately the years 460 AD to 800 AD, the Mount Pleasant Culture had a village on the Tillett Site in southern Roanoke Island, within the modern-day Wanchese township. After the year 800 AD, the village was occupied by the Colington Culture, a predecessor to the historic Roanoke tribe who were encountered by the 1584 English Expedition. The Roanoke people of the Tillett site had a semi-seasonal life style: they inhabited the area from early Spring to early Fall, and the village primarily was based on fishing. During this yearly period, inhabitants consumed chiefly shellfish. Oysters and clams were the most common food source, and the people left middens of shells that demonstrated their consumption. Roanoke women also gathered acorns and hackberry nuts