Concord lies at the midpoint of Musketaquid, a place where the Assabet River, a typical midsize New England stream, enters from the west to bisect the ribbon of meadowland, creating the Sudbury River to the south and the Concord River to the north. It’s no accident that Concord village was settled in this strategic spot, where three rivers touch—the axis mundi of a most unusual valley.
Eighteen miles. That’s the distance from Boston Harbor to Concord village. A regiment of British soldiers walked it on their ill-fated expedition. In October 1833, Thoreau hiked the route to Concord from his Harvard dormitory in Cambridge, blistering his feet in the process. Eighteen miles was far enough from the capital to serve as the primary depot of provincial military stores; it made for a long march in the dead of night through hostile countryside, as the British regulars learned to their sorrow. In times of peace, Concord could take advantage of its favorable location—far enough from more urban coastal settlements to cultivate a rural identity centered on agriculture, but close enough to enjoy proximity to educational institutions, literary culture, markets and wharves, and the statehouse. Concord became a right-size county seat, its central village of shops, taverns, courthouse, and meetinghouse surrounded by farms no more than a few minutes’ walk in any direction.
The physical separation between Boston and Concord involves more than the linear distance between two points. The population centers occupy different watersheds—the Charles River watershed to the east and the Concord River watershed to the west. In fact, they lie on different bedrock terranes that originated in different places in different eras. The terrane boundary coincides with the Bloody Bluff fault, named for a rocky notch where British troops were trapped by ferocious provincial fire. Here the land leans toward the security of the sea. To the west, it leans toward a hinterland where pioneering residents looked to one another for community support. Without the Lexington Road and its regular stagecoach traffic, 18th-century Concord would have remained an agricultural village. Instead, it became a prominent node in an expanding trade network. The significance of the watershed divide between country and city diminished only after the Fitchburg Railroad reached Concord in 1844.