| image = [[File:
Portsmouth Earthworks.jpg]]| caption = This map shows the Portsmouth earthworks. The Hopewellculture built these mounds and enclosures.
==100 B.C . to A.D. 500== The Hopewell culture is an ancient American Indian civilization that arose in Ohio and other parts of eastern North America during the Middle Woodland Period, perhaps as early as 100 BC. It is characterized by gigantic mounds and earthen enclosures in a variety of shapes, magnificent works of art crafted from raw materials brought to Ohio from great distances, and particular styles of stone tools and pottery unique to this time and region. The Hopewell culture developed from the preceding Adena culture , but the Hopewell culture built much larger earthworks and greatly expanded the area from which it obtained exotic raw materials, such as shells from the Gulf of Mexico, copper from the Great Lakes region, mica from the Carolinas, and obsidian from the Rocky Mountains. The archaeologist N'omi Greber refers to the rise of the Hopewell culture as an "explosion" of art, ritual, and ceremonial architecture. The earliest evidence for the Hopewell culture is in Illinois, but the most spectacular earthworks are in southern Ohio and Indiana north of the Ohio River, especially in the valleys of the Great and Little Miami, Scioto, and Muskingum rivers. The Newark Earthworks, Ohio's official prehistoric monument, is the largest set of geometric earthworks built by the Hopewell culture. The Fort Ancient Earthworks, in Warren County, is the largest example of a hilltop enclosure. The largest set of Hopewell burial mounds is at the Mound City Group in Chillicothe. All three of these sites are National Historic Landmarks and all are being considered for nomination as World Heritage sites. These large earthwork sites were not cities. They were places of ceremony, including rituals related to the burial of the honored dead. The Hopewell people lived in small villages, or hamlets, scattered throughout the river valleys of southern Ohio where they grew a variety of crops, including sunflower, squash, goosefoot, maygrass, and other plants with oily or starchy seeds. They also gathered wild plants, hunted for deer and other large and small game, and fished. The earthworks also must have served as places for these dispersed groups to gather periodically to renew friendships and socialize. The Hopewell culture had leaders, but they were not like powerful rulers who could command armies of slaves and soldiers. Many people from different villages worked together to build these large mounds and enclosures. The Hopewell "explosion" was brilliant, but brief. It was all over by AD 400. The reasons for the decline of the Hopewell culture are not well understood. The shift during the succeeding Late Woodland period to larger villages surrounded by walls or ditches hints that increasing conflict may have been one factor in the abandonment of the earthworks and the far-flung networks of exchange. It is important to emphasize that the Hopewell culture is not the name of an American Indian tribe. We do not know what these people might have called themselves. Instead, it is a term of archaeological convenience that encompasses similarities in artifact style, architecture, and other cultural practices that distinguish the Hopewell culture from earlier and later cultures in the region. The name comes from the name of the person who owned the Hopewell Mound Group in Chillicothe when archaeologists were investigating the site in the 1800s. The site exemplified all the significant features of the culture, so it became the "type site" and the name of the site was applied to the entire culture.