From Wikipedia

First Settlement Of The Americas

The Clovis culture (sometimes referred to as the Llano culture) is a prehistoric Paleoindian culture that first appears in the archaeological record of North America around 11,500 rcbp radiocarbon years ago, at the end of the last glacial period, characterized by a particular tool kit adapted to the hunting of large mammals. Archaeologists' best guess at present suggests this is equal to roughly 13,000 calendar years ago. The Clovis culture is thought to have lasted between 200 and 800 years, depending on the source consulted, with an average estimate of around 500 years, starting about 13,000 years ago. The Clovis culture was replaced by several more localized regional cultures from the time of the Younger Dryas cold climate period onward. Post-Clovis cultures include the Folsom tradition, Gainey, Suwannee-Simpson, Plainview-Goshen, Cumberland point, and Redstone. Each of these is commonly thought to derive directly from Clovis, in some cases apparently differing only in the length of the fluting on their projectile points. Although this is generally held to be the result of normal cultural change through time, numerous other reasons have been suggested to be the driving force for the observed changes in the archaeological record, such as an extraterrestrial impact event or post-glacial climate change with numerous extinctions.

After the discovery of several Clovis sites in western North America in the 1930s, the Clovis people came to be regarded as the first human inhabitants of the New World. Clovis people were thought to be the ancestors of all the indigenous cultures of North and South America. However, this view has been contested over the last thirty years by several archaeological discoveries, including sites like Cactus Hill in Virginia, Paisley Caves in the Summer Lake Basin of Oregon, the Topper site in Allendale County, South Carolina, Meadowcroft Rockshelter in Pennsylvania, and the Monte Verde and Cueva Fell sites in Chile.