When Boston Harbor was dry land, mastodons roamed. Tusked and shaggy, they foraged along a coastal plain that ended as sedimentary sludge eleven miles east of present-day Long Wharf. They wound their trunks around spruce branches and tugged sharply to dislodge a repast of sweet needles, unaware that their vast boreal habitat would soon be supplanted by sun-loving hardwoods. Occasionally, the beasts glanced up at a nearby drumlin. One could never be too careful of the growing bands of humans who so often lurked behind boulders, lying in ambush with fire and spears.

Such was Massachusetts ten thousand years ago, a land of warming climate and rising seas, home to megafauna on the brink of extinction. For the past million years, Earth had experienced dramatic climatic changes. Temperatures fluctuated, plunging the planet into ice ages interspersed with warmer periods. The most recent Ice Age – through which we are living today – began twenty-five thousand years Before Present (BP). Long winters and cool summers created a snowpack that eventually compacted into an ice sheet stretching from the Arctic to present-day New Jersey. At its maximum extent, the ice contained 5% of the planet’s water, lowering ocean levels by hundreds of feet. As the glaciers expanded and moved, they accumulated silt, pebbles, and boulders. These sediments were deposited when the glaciers began to melt around 18,000 BP, leaving a stony landscape of glacial features familiar to Bostonians today: moraines (Cape Cod), drumlins (the Harbor Islands, Bunker and Beacon Hills), and kettle ponds (Walden Pond), among others. By 14,000 BP, the ice sheet had completely receded from Massachusetts. What remained was a treeless, frigid tundra whose coastline would gradually disappear beneath waves of glacial meltwater.
As vegetation returned to the region, animals and ancient humans arrived as well. Paleo-Indians and their Archaic Period descendants (8,000-3,000 BP) settled along the coastline and rivers, where they enjoyed abundant fish, shellfish, and game. Over time, they transitioned from living in small bands to inhabiting villages. Archaic peoples led a hunter-gatherer lifestyle, migrating seasonally between hills and lowlands, forests and estuaries to secure food and supplies. They built canoes and fish weirs from wood, carved harpoons and awls from bone, and chiseled arrow and spear points, knives, pestles, and gaming pieces from stone. They wove baskets and decorated animal hide clothing with beads. Archaic peoples were deeply familiar with the Boston-area landscape and waterways. Such knowledge enabled Boston-area inhabitants to survive and thrive.

Archaeologists have identified many Archaic settlements throughout Boston. The Harbor Islands, popular fishing and clam digging sites, are littered with artifacts, from net weights to jewelry. In 1913 and the 1940s, subway construction workers unearthed four thousand-year-old fish weirs along Boylston Street, a former wetland. Later, in 1982, archaeologists discovered hearths, earthen pits, and various artifacts associated with hunting, stone tool production, and food preparation near the Charlestown Navy Yard – relics of three temporary occupation sites spanning the years between 5000 and 1,200 BP. This period witnessed the transformation of local Native civilization. Plants became a dietary staple to such an extent that villages began to develop agricultural practices. Emerging long-distance trade routes supplied people with goods from as far away as the Hudson River and, perhaps, the Great Lakes. Women used glacial deposits of clay to create ceramics, refining their artistry in ways that enable today’s archaeologists to date excavation sites by analyzing the pottery they contain. These dramatic developments in Northeast American civilization marked the transition from the Archaic to Early Woodland Periods. They gave rise to modern Native tribes and set the stage for the cultural and economic conditions that Europeans encountered when they first set foot in Massachusetts four hundred years ago.