The Merrimack Valley is a bi-state region along the Merrimack River in the U.S. states of New Hampshire and Massachusetts. The Merrimack is one of the larger waterways in New England and has helped to define the livelihood and culture of those living along it for millennia. Major cities in the Merrimack Valley include Concord, Manchester, and Nashua in New Hampshire, and Lowell, Lawrence, and Haverhill in Massachusetts. The Valley was a major center of the textile industry in the 19th century. Geography and demographics Massachusetts The Merrimack Valley area in Massachusetts is a community of towns and cities flanking the Merrimack River along the New Hampshire border, a portion of which is defined by a line approximately north and west of the Merrimack. The cities (marked with italics) and towns in this area are: Amesbury Andover Billerica Boxford Chelmsford Dracut Dunstable Georgetown Groveland Haverhill Lawrence LittletonLowellMerrimacMethuenNewburyNewburyportNorth Andover Rowley Salisbury Tewksbury Tyngsborough West Newbury Westford Wilmington The population of the region in 2010 was 631,477, slightly more than that of Boston, and about one tenth of the state's. The Merrimack Valley contains a mixture of 19th-century industrial cities and mill complexes built to take advantage of the river's waterpower, modern suburbs (many built over towns dating from the 17th century), and some relatively rural areas. The western part, including Greater Lowell and Haverhill–Lawrence–Methuen, is generally more urban than the eastern part. The entire Merrimack Valley region in Massachusetts is part of Greater Boston. Broader definitions for the region include other areas of Middlesex County, including the Route 2 corridor from Devens east to Lexington. Automobile travel through the Massachusetts section of the Merrimack Valley is served primarily by Interstate 495. From Lowell and Lawrence, U.S. Route 3 and Interstate 93, respectively, head north along the valley, joining in Manchester, New Hampshire. New Hampshire In New Hampshire, the Merrimack Valley Region is an area of the south-central part of the state, about wide, centered on the Merrimack River, and running from Canterbury south to the Massachusetts border. Henniker marks the western extent, and Nottingham the eastern. It includes parts of Hillsborough, Rockingham and Merrimack counties, namely the following towns and cities (in italics): Allenstown Amherst Atkinson Auburn Bedford Boscawen Bow Brookline Candia Canterbury Chester ChichesterConcordDeerfield Derry Dunbarton Epsom Goffstown Hampstead Henniker Hollis Hooksett Hopkinton Hudson Litchfield Londonderry LoudonManchesterMerrimack Milford Mont VernonNashua'' New Boston Northwood Nottingham Pelham Pembroke Raymond Salem Sandown Weare