Early Woodland Period (3,000‐2,000 years ago)

Fewer places have been found in the Northeast that date to the Early Woodland Period compared with earlier periods. Archaeologists think that fewer people may have lived in this region during this period, perhaps because of changing environmental conditions or unknown epidemic diseases. However, it may be instead that archaeological sites dating to this period have been mistakenly assigned to other time periods because some of the same types of artifacts were used and some of the same traditions were practiced during earlier and later periods. This may mean that some Early Woodland sites have been assigned to other periods by mistake.

Clay pots were made for storage and cooking. More stone tools were made from materials such as chert and jasper from outside New England. This indicates that indigenous people once again had long-distance connections with people in other regions.

Middle Woodland Period (2,000-1,000 years ago)

Local indigenous populations interacted with more groups living farther away. The larger base camps near rivers and the coast indicate that groups lived in one place longer than before and created storage pits for saving large amounts of food. Small groups continued to travel and occupy favored places seasonally for better access to food and other materials. In addition to hunting and fishing, Native people began to grow maize (corn). This grain came to the Northeast along trade routes from the southwest as far away as Mexico and Guatemala, but seemingly only to supplement their diet that relied more on animal protein with other sorts of wild and cultivated plants. In the 1940s, some amateur archaeologists found Middle Woodland artifacts at several places in Chelmsford.

Late Woodland Period (1,000-450 years ago)

Native Americans improved pottery technology to make more styles of ceramics. Groups relied on hunting and plant collecting for food, and some planted gardens with maize and squash. Local populations continued to occupy their ancestors' homelands. They continued some of their alliances with other Native peoples in and outside New England. Some social traditions helped to resolve conflicts among families, clans, villages, and tribes. Clans led by women were one of these traditions. Speaking multiple languages and dialects was useful for negotiations about territories and trade. Compared to indigenous groups in other parts of North America, violence and war occurred less often in the Northeast.

The remains of Late Woodland hearths and items used for cooking have been found in Chelmsford and other areas in the lower Merrimack River drainage. Hearths were used for cooking and heating, and wood racks were built to dry and smoke meat and fish. Fires were built on platforms of closely packed rocks. The fire heated the rocks for roasting, drying, or steaming food. The platforms also may have been used to prepare reeds to make mats and baskets.